AB(diag)-42
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
17.Diagnostic Chart with Trouble Code
A: DTC U0073 CONTROL MODULE COMMUNICATION BUS OFF
DIAGNOSIS START CONDITION:
Ignition voltage remains at 10 V or more for 1 second.
DTC DETECTING CONDITION:
This is detected when a CAN line malfunction occurs.
NOTE:
Perform the diagnosis for LAN system. <Ref. to LAN(diag)-2, PROCEDURE, Basic Diagnostic Procedure.>
B: DTC B1000 AIRBAG ECU MALFUNCTION
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
Step Check Yes No
1 CHECK DTC.
Read the DTC. (Current malfunction) <Ref. to
AB(diag)-25, Read Diagnostic Trouble Code
(DTC).>
Is any of B1000, B1003, B1105,
B1106, B1115, B1116, B1170,
B1185, B1195, B1196 or
B1199 displayed?
Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Perform the Clear
Memory Mode.
<Ref. to AB(diag)-
27, Clear Memory
Mode.>
15WRX_STI_US_EN.book 42 ペー   
AB(diag)-43
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
C: DTC B1003 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1103 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
D: DTC B1105 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1105 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
E: DTC B1106 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1106 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
F: DTC B1115 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1115 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
G: DTC B1116 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1116 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
H: DTC B1170 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1170 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
I: DTC B1185 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1185 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
J: DTC B1195 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1195 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
K: DTC B1196 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1196 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
L: DTC B1199 AIRBAG ECU MALFUNCTION
NOTE:
Refer to DTC B1199 for details on DTC B1000. <Ref. to AB(diag)-42, DTC B1000 AIRBAG ECU MALFUNC-
TION, Diagnostic Chart with Trouble Code.>
15WRX_STI_US_EN.book 43 ペー   
AB(diag)-44
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
M: DTC B11E0 ROLLOVER IGNITION
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
This DTC is indicated when the curtain airbag module and the seat belt pretensioner are deployed.
Once this DTC is displayed, the memory cannot be cleared. Replace the following parts.
Airbag control module <Ref. to AB-48, Airbag Control Module.>
Curtain airbag module <Ref. to AB-46, Curtain Airbag Module.>
Front outer seat belt with pretensioner <Ref. to SB-16, Front Seat Belt.>
N: DTC B11F2 FRONT IMPACT IGNITION
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
This DTC is indicated when the front airbag module and the pretensioner are deployed.
Once this DTC is displayed, the memory cannot be cleared. Therefore replace the following parts.
Airbag control module <Ref. to AB-48, Airbag Control Module.>
Driver’s airbag module <Ref. to AB-33, Driver’s Airbag Module.>
Passenger’s airbag module <Ref. to AB-36, Passenger’s Airbag Module.>
Driver’s knee airbag module <Ref. to AB-35, Knee Airbag Module.>
Front sub sensor of both sides <Ref. to AB-50, Front Sub Sensor.>
Front outer seat belt with pretensioner of both sides <Ref. to SB-16, Front Seat Belt.>
Steering roll connector <Ref. to AB-60, Roll Connector.>
Occupant detection system (passenger’s seat cushion & frame assembly) <Ref. to SE-9, Front Seat.>
Side airbag module on both sides (when activated) <Ref. to AB-54, Side Airbag Sensor.>
Curtain airbag module on both sides (when activated) <Ref. to AB-46, Curtain Airbag Module.>
O: DTC B11F3 FRONT IMPACT IGNITION
NOTE:
For details on DTC B11F3, refer to DTC B11F2. <Ref. to AB(diag)-44, DTC B11F2 FRONT IMPACT IGNI-
TION, Diagnostic Chart with Trouble Code.>
P: DTC B11F4 FRONT IMPACT IGNITION
NOTE:
For details on DTC B11F4, refer to DTC B11F2. <Ref. to AB(diag)-44, DTC B11F2 FRONT IMPACT IGNI-
TION, Diagnostic Chart with Trouble Code.>
Q: DTC B11F5 FRONT IMPACT IGNITION
NOTE:
For details on DTC B11F5, refer to DTC B11F2. <Ref. to AB(diag)-44, DTC B11F2 FRONT IMPACT IGNI-
TION, Diagnostic Chart with Trouble Code.>
15WRX_STI_US_EN.book 44 ペー   
AB(diag)-45
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
R: DTC B11F7 SIDE IMPACT IGNITION
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
This DTC is displayed when the side airbag module and curtain airbag module are deployed.
Once this DTC is displayed, the memory cannot be cleared. Replace the following parts.
Airbag control module <Ref. to AB-48, Airbag Control Module.>
Side airbag module (operating side) <Ref. to AB-43, Side Airbag Module.>
Side airbag sensor (operating side) <Ref. to AB-54, Side Airbag Sensor.>
Curtain airbag module (operating side) <Ref. to AB-46, Curtain Airbag Module.>
Curtain airbag sensor (operating side) <Ref. to AB-56, Curtain Airbag Sensor.>
Satellite safing sensor <Ref. to AB-58, Satellite Safing Sensor.>
Front door impact sensor (operating side) <Ref. to AB-52, Front Door Impact Sensor.>
Front outer seat belt with pretensioner on the collision side (when activated) <Ref. to SB-16, Front Seat
Belt.>
S: DTC B11F8 SIDE IMPACT IGNITION
NOTE:
For details on DTC B11F8. refer to DTC B11F7. <Ref. to AB(diag)-45, DTC B11F7 SIDE IMPACT IGNITION,
Diagnostic Chart with Trouble Code.>
T: DTC B11F9 SIDE IMPACT IGNITION
NOTE:
For details on DTC B11F9, refer to DTC B11F7. <Ref. to AB(diag)-45, DTC B11F7 SIDE IMPACT IGNITION,
Diagnostic Chart with Trouble Code.>
U: DTC B11FA SIDE IMPACT IGNITION
NOTE:
For details on DTC B11FA, refer to DTC B11F7. <Ref. to AB(diag)-45, DTC B11F7 SIDE IMPACT IGNITION,
Diagnostic Chart with Trouble Code.>
V: DTC B11FB SIDE IMPACT IGNITION
NOTE:
For details on DTC B11FB, refer to DTC B11F7. <Ref. to AB(diag)-45, DTC B11F7 SIDE IMPACT IGNITION,
Diagnostic Chart with Trouble Code.>
W: DTC B11FC SIDE IMPACT IGNITION
NOTE:
For details on DTC B11FC, refer to DTC B11F7. <Ref. to AB(diag)-45, DTC B11F7 SIDE IMPACT IGNITION,
Diagnostic Chart with Trouble Code.>
X: DTC B1610 FRONT SUB SENSOR RH FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Front sub sensor RH is faulty.
If DTC B1610 is displayed, the circuit within the front sub sensor RH is faulty.
Replace the front sub sensor RH. <Ref. to AB-50, Front Sub Sensor.>
Y: DTC B1612 FRONT SUB SENSOR RH LOST COMMUNICATION
NOTE:
For details on DTC B1612, refer to DTC B1613. <Ref. to AB(diag)-46, DTC B1613 FRONT SUB SENSOR
RH INITIALIZATION ERROR, Diagnostic Chart with Trouble Code.>
15WRX_STI_US_EN.book 45 ペー   
AB(diag)-46
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
Z: DTC B1613 FRONT SUB SENSOR RH INITIALIZATION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of front sensor bus RH.
Front sub sensor RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors (AB6,
AB16) between the airbag control module and
the front sub sensor RH.
Is there poor contact? Replace the airbag
main harness
along with body
harness.
Go to step 2.
AB-02830
12
AB6
1234567
8
9
10
11 12 13 14
15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
AB16
92
72
AB16
1
2
AB6
FRONT SUB SENSOR RH
AIRBAG CM
15WRX_STI_US_EN.book 46 ペー   
AB(diag)-47
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tors (AB7) and (AB2).
3) Remove the console front panel and discon-
nect the connector (AB9).
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
6) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
7) Disconnect the connector (AB16) from the
front sub sensor RH, and then connect the con-
nector (1H) in the test harness H to connector
(AB16).
8) Measure the resistance between connector
(4AG) in the test harness AG and connector
(3H) in the test harness H.
Connector & terminal
(4AG) No. 14 — (3H) No. 5:
(4AG) No. 12 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS RH).
Measure the resistance between connector
(4AG) in the test harness AG and chassis
ground, and the resistance between connector
(4AG) terminals in the test harness AG.
Connector & terminal
(4AG) No. 12 — Chassis ground:
(4AG) No. 14 — Chassis ground:
(4AG) No. 12 — (4AG) No. 14:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
main harness
along with body
harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the front
sub sensor RH.
<Ref. to AB-50,
REMOVAL, Front
Sub Sensor.>
Replace the airbag
control module if
not operating nor-
mally even after
replacing the sen-
sor. <Ref. to AB-
48, REMOVAL, Air-
bag Control Mod-
ule.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code”.
<Ref. to AB(diag)-
33, List of Diagnos-
tic Trouble Code
(DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 47 ペー   
AB(diag)-48
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AA:DTC B1615 FRONT SUB SENSOR LH FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Front sub sensor LH is faulty.
If DTC B1615 is displayed, the circuit within the front sub sensor LH is faulty.
Replace the front sub sensor LH. <Ref. to AB-50, Front Sub Sensor.>
AB:DTC B1617 FRONT SUB SENSOR LH LOST COMMUNICATION
NOTE:
For details on DTC B1617, refer to DTC B1618. <Ref. to AB(diag)-49, DTC B1618 FRONT SUB SENSOR
LH INITIALIZATION ERROR, Diagnostic Chart with Trouble Code.>
15WRX_STI_US_EN.book 48 ペー   
AB(diag)-49
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AC:DTC B1618 FRONT SUB SENSOR LH INITIALIZATION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of front sensor bus LH.
Front sub sensor LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors (AB6,
AB13) between the airbag control module and
the front sub sensor LH.
Is there poor contact? Replace the airbag
main harness
along with body
harness.
Go to step 2.
AB-02831
12
AB6
1234567
8
9
10
11 12 13 14
15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
AB13
03
82
AB13
1
2
AB6
FRONT SUB SENSOR LH
AIRBAG CM
15WRX_STI_US_EN.book 49 ペー   
AB(diag)-50
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tors (AB7) and (AB2).
3) Remove the console front panel and discon-
nect the connector (AB9).
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
6) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
7) Disconnect the connector (AB13) from the
front sub sensor LH, and then connect the con-
nector (1H) in the test harness H to connector
(AB13).
8) Measure the resistance between connector
(4AG) in the test harness AG and connector
(3H) in the test harness H.
Connector & terminal
(4AG) No. 7 — (3H) No. 5:
(4AG) No. 9 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS LH).
Measure the resistance between connector
(4AG) in the test harness AG and chassis
ground, and the resistance between connector
(4AG) terminals in the test harness AG.
Connector & terminal
(4AG) No. 7 — Chassis ground:
(4AG) No. 9 — Chassis ground:
(4AG) No. 7 — (4AG) No. 9:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
main harness
along with body
harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the front
sub sensor LH.
<Ref. to AB-50,
REMOVAL, Front
Sub Sensor.>
Replace the airbag
control module if
not operating nor-
mally even after
replacing the sen-
sor. <Ref. to AB-
48, REMOVAL, Air-
bag Control Mod-
ule.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code”.
<Ref. to AB(diag)-
33, List of Diagnos-
tic Trouble Code
(DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 50 ペー   
AB(diag)-51
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AD:DTC B16F2 FRONT SUB SENSOR RH RECOGNITION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Front sub sensor RH is wrongly installed.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
AE:DTC B16F3 FRONT SUB SENSOR LH RECOGNITION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Front sub sensor LH is wrongly installed.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
AF:DTC B1620 SIDE AIRBAG SENSOR RH FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag sensor RH is faulty.
When DTC B1620 is displayed, the circuit within the side airbag sensor RH is faulty.
Replace the side airbag sensor RH. <Ref. to AB-54, Side Airbag Sensor.>
AG:DTC B1622 SIDE AIRBAG SENSOR RH LOST COMMUNICATION
NOTE:
For details on DTC B1622, refer to DTC B1623. <Ref. to AB(diag)-52, DTC B1623 SIDE AIRBAG SENSOR
RH INITIALIZATION ERROR, Diagnostic Chart with Trouble Code.>
Step Check Yes No
1 REPLACE FRONT SUB SENSOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the front sub sensor RH with a gen-
uine sensor. <Ref. to AB-50, REMOVAL, Front
Sub Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Step Check Yes No
1 REPLACE FRONT SUB SENSOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the front sub sensor LH with a gen-
uine sensor. <Ref. to AB-50, REMOVAL, Front
Sub Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
15WRX_STI_US_EN.book 51 ペー   
AB(diag)-52
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AH:DTC B1623 SIDE AIRBAG SENSOR RH INITIALIZATION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of side sensor bus RH.
Side airbag sensor RH and curtain airbag sensor RH are faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the side
airbag sensor RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
10
9
6
7
11
8
AB33
2
1
12
AB33
AB18
AB28
AB34
31
2
4
31
2
4
AB24
AB64
2
1
AB24
3
2
4
3
2
1
AB28
AB-03477
AIRBAG CM
CURTAIN
AIRBAG
SENSOR RH
SIDE
AIRBAG
MODULE RH
SIDE
AIRBAG
SENSOR RH
CURTAIN
AIRBAG
MODULE RH
FRONT
DOOR IMPACT
SENSOR RH
15WRX_STI_US_EN.book 52 ペー   
AB(diag)-53
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the connector (AB24) of side
airbag module RH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Disconnect the connector (AB28) from side
airbag sensor RH, and connect the connector
(2V) in test harness V to connector (AB28).
9) Measure the resistance between connector
(5AG) in the test harness AG and connector
(3V) in the test harness V.
Connector & terminal
(5AG) No. 14 — (3V) No. 1:
(5AG) No. 15 — (3V) No. 2:
Is the resistance less than 10
Ω?
Go to step 3. Replace the airbag
rear harness along
with body harness.
3 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR RH).
Measure the resistance between test harness
AG connectors (5AG) and chassis ground, and
the resistance between connectors (5AG) of the
test harness AG.
Connector & terminal
(3V) No. 1 — Chassis ground:
(3V) No. 2 — Chassis ground:
(3V) No. 1 — (3V) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 5. Go to step 6.
5 REPLACE SIDE AIRBAG SENSOR RH AND
CHECK AIRBAG CONTROL MODULE AF-
TER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the side airbag sensor RH. <Ref. to
AB-54, REMOVAL, Side Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the system normal? Go to step 6. Replace the cur-
tain airbag sensor
RH. <Ref. to AB-
56, REMOVAL,
Curtain Airbag
Sensor.> Replace
the airbag control
module if not oper-
ating normally
even after replac-
ing the sensor.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Step Check Yes No
15WRX_STI_US_EN.book 53 ペー   
AB(diag)-54
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AI: DTC B1625 SIDE AIRBAG SENSOR LH FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag sensor LH is faulty.
When DTC B1625 is displayed, the circuit within the side airbag sensor LH is faulty.
Replace the side airbag sensor LH. <Ref. to AB-54, Side Airbag Sensor.>
AJ:DTC B1627 SIDE AIRBAG SENSOR LH LOST COMMUNICATION
NOTE:
Refer to DTC B1627 for details on DTC B1628. <Ref. to AB(diag)-55, DTC B1628 SIDE AIRBAG SENSOR
LH INITIALIZATION ERROR, Diagnostic Chart with Trouble Code.>
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 54 ペー   
AB(diag)-55
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AK:DTC B1628 SIDE AIRBAG SENSOR LH INITIALIZATION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of side sensor bus LH.
Side airbag sensor LH and curtain airbag sensor LH are faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the side
airbag sensor LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
AB17
13
8
3
1211
76
14 15
9
10
4251
12
AB62AB58
1
2
12
AB31
AB23
AB32
31
2
4
31
2
4
AB19
1
2
AB62 R123
4
3
2
1
AB32
6
7
9
10
15
8
AB31
2
1
AB17
AB58
2
1
AB19
2
3
4
3
2
1
AB23
AB-03478
AIRBAG CM
CURTAIN
AIRBAG
SENSOR LH
SIDE
AIRBAG
MODULE LH
SIDE
AIRBAG
SENSOR LH
CURTAIN
AIRBAG
MODULE LH
FRONT
DOOR IMPACT
SENSOR LH
15WRX_STI_US_EN.book 55 ペー   
AB(diag)-56
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB31) from cur-
tain airbag module LH.
4) Disconnect the connector (AB19) of the side
airbag module LH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Disconnect the connector (AB23) from side
airbag sensor LH, and connect the connector
(2V) in test harness V to connector (AB23).
9) Measure the resistance between connector
(5AG) in the test harness AG and connector
(3V) in the test harness V.
Connector & terminal
(5AG) No. 9 — (3V) No. 2:
(5AG) No. 10 — (3V) No. 1:
Is the resistance less than 10
Ω?
Go to step 3. Replace the airbag
rear harness along
with body harness.
3 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR LH).
Measure the resistance between test harness
AG connectors (5AG) and chassis ground, and
the resistance between connectors (5AG) of the
test harness AG.
Connector & terminal
(3V) No. 1 — Chassis ground:
(3V) No. 2 — Chassis ground:
(3V) No. 1 — (3V) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 5. Go to step 6.
5 REPLACE SIDE AIRBAG SENSOR LH AND
CHECK AIRBAG CONTROL MODULE AF-
TER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the side airbag sensor LH. <Ref. to
AB-54, REMOVAL, Side Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the system normal? Go to step 6. Replace the cur-
tain airbag sensor
LH. <Ref. to AB-
56, REMOVAL,
Curtain Airbag
Sensor.> Replace
the airbag control
module if not oper-
ating normally
even after replac-
ing the sensor.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Step Check Yes No
15WRX_STI_US_EN.book 56 ペー   
AB(diag)-57
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AL:DTC B1630 CURTAIN AIRBAG SENSOR RH FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag sensor RH is faulty.
If DTC B1630 is displayed, the circuit within the curtain airbag sensor RH is faulty.
Replace the curtain airbag sensor RH. <Ref. to AB-56, Curtain Airbag Sensor.>
AM:DTC B1632 CURTAIN AIRBAG SENSOR RH LOST COMMUNICATION
NOTE:
Refer to DTC B1632 for details on DTC B1633. <Ref. to AB(diag)-58, DTC B1633 CURTAIN AIRBAG SEN-
SOR RH INITIALIZATION ERROR, Diagnostic Chart with Trouble Code.>
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 57 ペー   
AB(diag)-58
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AN:DTC B1633 CURTAIN AIRBAG SENSOR RH INITIALIZATION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of side sensor bus RH.
Side airbag sensor RH and curtain airbag sensor RH are faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1622 or B1623 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 2.
2 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the door
sensor RH.
Is there poor contact? Replace the airbag
rear harness and
the door harness.
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
10
9
6
7
11
8
AB33
2
1
12
AB33
AB18
AB28
AB34
31
2
4
31
2
4
AB24
AB64
2
1
AB24
3
2
4
3
2
1
AB28
AB-03477
AIRBAG CM
CURTAIN
AIRBAG
SENSOR RH
SIDE
AIRBAG
MODULE RH
SIDE
AIRBAG
SENSOR RH
CURTAIN
AIRBAG
MODULE RH
FRONT
DOOR IMPACT
SENSOR RH
15WRX_STI_US_EN.book 58 ペー   
AB(diag)-59
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR RH AND
CURTAIN AIRBAG SENSOR RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the connector (AB24) of side
airbag module RH.
5) Disconnect the connector (AB28) of side
airbag sensor RH.
6) Connect the connector (AB28) of side air-
bag sensor RH and the connector (1AI) in the
test harness AI.
7) Connect the connector (2AI) in the test har-
ness AI and the connector (1V) in the test har-
ness V.
8) Disconnect the connector (AB34) from cur-
tain airbag sensor (RH), and connect the con-
nector (2V) in test harness V to connector
(AB34).
9) Measure the resistance between connector
(3V) terminals in the test harness V.
Connector & terminal
(3V) No. 2 — (3V) No. 6:
(3V) No. 1 — (3V) No. 7:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR AND CUR-
TAIN AIRBAG SENSOR RH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) in test
harness V.
Connector & terminal
(3V) No. 2 — Chassis ground:
(3V) No. 1 — Chassis ground:
(3V) No. 2 — (3V) No. 1:
Is the resistance 1 MΩ or
more?
Go to step 5. Replace the airbag
rear harness along
with body harness.
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 6. Go to step 7.
6 REPLACE CURTAIN AIRBAG SENSOR RH
AND CHECK AIRBAG CONTROL MODULE
AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the curtain airbag sensor RH.
<Ref. to AB-56, REMOVAL, Curtain Airbag
Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 7. Go to step 8.
Step Check Yes No
15WRX_STI_US_EN.book 59 ペー   
AB(diag)-60
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AO:DTC B1635 CURTAIN AIRBAG SENSOR LH FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag sensor LH is faulty.
If DTC B1635 is displayed, the circuit within the curtain airbag sensor LH is faulty.
Replace the curtain airbag sensor LH. <Ref. to AB-56, Curtain Airbag Sensor.>
AP:DTC B1637 CURTAIN AIRBAG SENSOR LH LOST COMMUNICATION
NOTE:
Refer to DTC B1637 for details on DTC B1638. <Ref. to AB(diag)-61, DTC B1638 CURTAIN AIRBAG SEN-
SOR LH INITIALIZATION ERROR, Diagnostic Chart with Trouble Code.>
7 REPLACE SIDE AIRBAG SENSOR RH AND
CHECK AIRBAG CONTROL MODULE AF-
TER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the side airbag sensor RH. <Ref. to
AB-54, REMOVAL, Side Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 8.
8 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 60 ペー   
AB(diag)-61
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AQ:DTC B1638 CURTAIN AIRBAG SENSOR LH INITIALIZATION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of side sensor bus LH.
Side airbag sensor LH and curtain airbag sensor LH are faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1627 or B1628 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 2.
2 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the door
sensor LH.
Is there poor contact? Replace the airbag
rear harness and
the door harness.
Go to step 3.
AB17
13
8
3
1211
76
14 15
9
10
4251
12
AB62AB58
1
2
12
AB31
AB23
AB32
31
2
4
31
2
4
AB19
1
2
AB62 R123
4
3
2
1
AB32
6
7
9
10
15
8
AB31
2
1
AB17
AB58
2
1
AB19
2
3
4
3
2
1
AB23
AB-03478
AIRBAG CM
CURTAIN
AIRBAG
SENSOR LH
SIDE
AIRBAG
MODULE LH
SIDE
AIRBAG
SENSOR LH
CURTAIN
AIRBAG
MODULE LH
FRONT
DOOR IMPACT
SENSOR LH
15WRX_STI_US_EN.book 61 ペー   
AB(diag)-62
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR LH AND
CURTAIN AIRBAG SENSOR LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB31) from cur-
tain airbag module LH.
4) Disconnect the connector (AB19) of the side
airbag module LH.
5) Disconnect the connector (AB23) in the side
airbag sensor LH.
6) Connect the connector (AB23) of side air-
bag sensor LH and the connector (1AI) in the
test harness AI.
7) Connect the connector (2AI) in the test har-
ness AI and the connector (1V) in the test har-
ness V.
8) Disconnect the connector (AB32) from cur-
tain airbag sensor LH, and connect it to the con-
nector (2V) in test harness V.
9) Measure the resistance between connector
(3V) terminals in the test harness V.
Connector & terminal
(3V) No. 2 — (3V) No. 6:
(3V) No. 1 — (3V) No. 7:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR AND CUR-
TAIN AIRBAG SENSOR LH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) in test
harness V.
Connector & terminal
(3V) No. 1 — Chassis ground:
(3V) No. 2 — Chassis ground:
(3V) No. 1 — (3V) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 5. Replace the airbag
rear harness along
with body harness.
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 6. Go to step 8.
6 REPLACE CURTAIN AIRBAG SENSOR LH
AND CHECK AIRBAG CONTROL MODULE
AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the curtain airbag sensor LH. <Ref.
to AB-56, REMOVAL, Curtain Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 7. Go to step 8.
Step Check Yes No
15WRX_STI_US_EN.book 62 ペー   
AB(diag)-63
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
7 REPLACE SIDE AIRBAG SENSOR LH AND
CHECK AIRBAG CONTROL MODULE AF-
TER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the side airbag sensor LH. <Ref. to
AB-54, REMOVAL, Side Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 8.
8 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 63 ペー   
AB(diag)-64
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AR:DTC B16F4 SIDE AIRBAG SENSOR RH RECOGNITION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag sensor RH is misinstalled.
Airbag CM is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
AS:DTC B16F5 SIDE AIRBAG SENSOR LH RECOGNITION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag sensor LH is misinstalled.
Airbag CM is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
Step Check Yes No
1 REPLACE SIDE AIRBAG SENSOR RH.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the side airbag sensor RH with a
genuine sensor. <Ref. to AB-54, REMOVAL,
Side Airbag Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Step Check Yes No
1 REPLACE SIDE AIRBAG SENSOR LH.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the side airbag sensor LH with a
genuine sensor. <Ref. to AB-54, REMOVAL,
Side Airbag Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
15WRX_STI_US_EN.book 64 ペー   
AB(diag)-65
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AT:DTC B16F6 CURTAIN AIRBAG SENSOR RH RECOGNITION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag sensor RH is misinstalled.
Airbag CM is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
AU:DTC B16F7 CURTAIN AIRBAG SENSOR LH RECOGNITION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag sensor LH is misinstalled.
Airbag CM is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
Step Check Yes No
1 REPLACE CURTAIN AIRBAG SENSOR RH.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the curtain airbag sensor RH with a
genuine sensor. <Ref. to AB-56, REMOVAL,
Curtain Airbag Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Step Check Yes No
1 REPLACE CURTAIN AIRBAG SENSOR LH.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the curtain airbag sensor LH with a
genuine sensor. <Ref. to AB-56, REMOVAL,
Curtain Airbag Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
15WRX_STI_US_EN.book 65 ペー   
AB(diag)-66
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AV:DTC B1642 SIDE SATELLITE SENSOR BUS RH LOST COMMUNICATION
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of side sensor bus RH.
Side airbag sensor RH is faulty.
Curtain airbag sensor RH is faulty.
Front door impact sensor RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1622 or B1623 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 2.
2 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1632 or B1633 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 3.
3 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1692 or B1693 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 4.
4 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the front
door impact sensor RH.
Is there poor contact? Replace the airbag
rear harness and
the door harness.
Go to step 5.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
10
9
6
7
11
8
AB33
2
1
12
AB33
AB18
AB28
AB34
31
2
4
31
2
4
AB24
AB64
2
1
AB24
3
2
4
3
2
1
AB28
AB-03477
AIRBAG CM
CURTAIN
AIRBAG
SENSOR RH
SIDE
AIRBAG
MODULE RH
SIDE
AIRBAG
SENSOR RH
CURTAIN
AIRBAG
MODULE RH
FRONT
DOOR IMPACT
SENSOR RH
15WRX_STI_US_EN.book 66 ペー   
AB(diag)-67
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
5 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the connector (AB24) of side
airbag module RH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Disconnect the connector (AB28) from side
airbag sensor RH.
9) Connect the connector (2V) in the test har-
ness V to the connector (AB28).
10) Measure the resistance between connector
(5AG) in the test harness AG and connector
(3V) in the test harness V.
Connector & terminal
(5AG) No. 14 — (3V) No. 1:
(5AG) No. 15 — (3V) No. 2:
Is the resistance less than 10
Ω?
Go to step 6. Replace the airbag
rear harness along
with body harness.
6 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR RH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) termi-
nals.
Connector & terminal
(3V) No. 1 — Chassis ground:
(3V) No. 2 — Chassis ground:
(3V) No. 1 — (3V) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 7. Replace the airbag
rear harness along
with body harness.
Step Check Yes No
15WRX_STI_US_EN.book 67 ペー   
AB(diag)-68
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
7 CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR AND CUR-
TAIN AIRBAG SENSOR RH).
1) Disconnect the connector (2V) in the test
harness V from the connector (AB28) of side
airbag sensor RH.
2) Connect the connector (AB28) of side air-
bag sensor RH and the connector (1AI) in the
test harness AI.
3) Connect the connector (2AI) in the test har-
ness AI and the connector (1V) in the test har-
ness V.
4) Disconnect the connector (AB34) from cur-
tain airbag sensor (RH), and connect the con-
nector (2V) in test harness V to connector
(AB34).
5) Measure the resistance between connector
(3V) terminals in the test harness V.
Connector & terminal
(3V) No. 2 — (3V) No. 6:
(3V) No. 1 — (3V) No. 7:
Is the resistance less than 10
Ω?
Go to step 8. Replace the airbag
rear harness along
with body harness.
8 CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR AND CUR-
TAIN AIRBAG SENSOR RH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) termi-
nals in test harness V.
Connector & terminal
(3V) No. 2 — Chassis ground:
(3V) No. 1 — Chassis ground:
(3V) No. 1 — (3V) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 9. Replace the airbag
rear harness along
with body harness.
9 CHECK AIRBAG REAR HARNESS AND
DOOR HARNESS (BETWEEN CURTAIN AIR-
BAG SENSOR RH AND DOOR SENSOR RH).
1) Disconnect the connector (AB64) from the
front door impact sensor RH, and connect the
connector (1H) in the test harness H to connec-
tor (AB64).
2) Measure the resistance between connector
(3V) in the test harness V and connector (3H) in
the test harness H.
Connector & terminal
(3V) No. 4 — (3H) No. 5:
(3V) No. 5 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 10. Check the door
harness, and if any
fault is found,
replace the har-
ness. If there is no
fault, replace the
airbag rear har-
ness together with
body harness.
10 CHECK AIRBAG REAR HARNESS AND
DOOR HARNESS (BETWEEN CURTAIN AIR-
BAG SENSOR RH AND FRONT DOOR IM-
PACT SENSOR RH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) termi-
nals in test harness V.
Connector & terminal
(3V) No. 4 — Chassis ground:
(3V) No. 5 — Chassis ground:
(3V) No. 4 — (3V) No. 5:
Is the resistance 1 MΩ or
more?
Go to step 11. Check the door
harness, and if any
fault is found,
replace the har-
ness. If there is no
fault, replace the
airbag rear har-
ness together with
body harness.
Step Check Yes No
15WRX_STI_US_EN.book 68 ペー   
AB(diag)-69
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
11 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 12. Go to step 15.
12 REPLACE SIDE AIRBAG SENSOR RH AND
CHECK AIRBAG CONTROL MODULE AF-
TER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the side airbag sensor RH. <Ref. to
AB-54, REMOVAL, Side Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 13. Go to step 15.
13 REPLACE CURTAIN AIRBAG SENSOR RH
AND CHECK AIRBAG CONTROL MODULE
AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the curtain airbag sensor RH.
<Ref. to AB-56, REMOVAL, Curtain Airbag
Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 14. Go to step 15.
14 REPLACE FRONT DOOR IMPACT SENSOR
RH AND CHECK AIRBAG CONTROL MOD-
ULE AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the front door impact sensor RH.
<Ref. to AB-52, REMOVAL, Front Door Impact
Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 15.
15 CHECK FOR ANY OTHER DTC ON DISPLAY.
Read the DTC. (Current malfunction)
Is any other DTC displayed? Perform the diag-
nosis according to
DTC.
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 69 ペー   
AB(diag)-70
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AW:DTC B1647 SIDE SATELLITE SENSOR BUS LH LOST COMMUNICATION
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of side sensor bus LH.
Side airbag sensor LH is faulty.
Curtain airbag sensor LH is faulty.
Front door impact sensor LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1627 or B1628 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 2.
2 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1637 or B1638 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 3.
3 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1697 or B1698 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 4.
4 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the front
door impact sensor LH.
Is there poor contact? Replace the airbag
rear harness and
the door harness.
Go to step 5.
AB17
13
8
3
1211
76
14 15
9
10
4251
12
AB62AB58
1
2
12
AB31
AB23
AB32
31
2
4
31
2
4
AB19
1
2
AB62 R123
4
3
2
1
AB32
6
7
9
10
15
8
AB31
2
1
AB17
AB58
2
1
AB19
2
3
4
3
2
1
AB23
AB-03478
AIRBAG CM
CURTAIN
AIRBAG
SENSOR LH
SIDE
AIRBAG
MODULE LH
SIDE
AIRBAG
SENSOR LH
CURTAIN
AIRBAG
MODULE LH
FRONT
DOOR IMPACT
SENSOR LH
15WRX_STI_US_EN.book 70 ペー   
AB(diag)-71
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
5 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB31) from cur-
tain airbag module LH.
4) Disconnect the connector (AB19) of the side
airbag module LH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Disconnect the connector (AB23) from the
side airbag sensor LH.
9) Connect the connector (2V) in the test har-
ness V to the connector (AB23).
10) Measure the resistance between connector
(5AG) in the test harness AG and connector
(3V) in the test harness V.
Connector & terminal
(5AG) No. 10 — (3V) No. 1:
(5AG) No. 9 — (3V) No. 2:
Is the resistance less than 10
Ω?
Go to step 6. Replace the airbag
rear harness along
with body harness.
6 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SIDE AIRBAG SENSOR LH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) termi-
nals.
Connector & terminal
(3V) No. 1 — Chassis ground:
(3V) No. 2 — Chassis ground:
(3V) No. 1 — (3V) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 7. Replace the airbag
rear harness along
with body harness.
7 CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR AND CUR-
TAIN AIRBAG SENSOR LH).
1) Disconnect the connector (2V) in the test
harness V from the connector (AB23) of side
airbag sensor LH.
2) Connect the connector (AB23) of side air-
bag sensor LH and the connector (1AI) in the
test harness AI.
3) Connect the connector (2AI) in the test har-
ness AI and the connector (1V) in the test har-
ness V.
4) Disconnect the connector (AB32) from cur-
tain airbag sensor LH, and connect the connec-
tor (2V) in test harness V to connector (AB32).
5) Measure the resistance between connector
(3V) terminals in the test harness V.
Connector & terminal
(3V) No. 2 — (3V) No. 6:
(3V) No. 1 — (3V) No. 7:
Is the resistance less than 10
Ω?
Go to step 8. Replace the airbag
rear harness along
with body harness.
Step Check Yes No
15WRX_STI_US_EN.book 71 ペー   
AB(diag)-72
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
8 CHECK AIRBAG REAR HARNESS (BE-
TWEEN SIDE AIRBAG SENSOR AND CUR-
TAIN AIRBAG SENSOR LH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) termi-
nals in test harness V.
Connector & terminal
(3V) No. 2 — Chassis ground:
(3V) No. 1 — Chassis ground:
(3V) No. 1 — (3V) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 9. Replace the airbag
rear harness along
with body harness.
9 CHECK AIRBAG REAR HARNESS AND
DOOR HARNESS (BETWEEN CURTAIN AIR-
BAG SENSOR LH AND DOOR SENSOR LH).
1) Disconnect the connector (AB58) from the
front door impact sensor LH, and connect the
connector (1H) in the test harness H to connec-
tor (AB58).
2) Measure the resistance between connector
(3V) in the test harness V and connector (3H) in
the test harness H.
Connector & terminal
(3V) No. 4 — (3H) No. 5:
(3V) No. 5 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 10. Check the door
harness, and if any
fault is found,
replace the har-
ness. If there is no
fault, replace the
airbag rear har-
ness together with
body harness.
10 CHECK AIRBAG REAR HARNESS AND
DOOR HARNESS (BETWEEN CURTAIN AIR-
BAG SENSOR LH AND DOOR SENSOR LH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) termi-
nals in test harness V.
Connector & terminal
(3V) No. 4 — Chassis ground:
(3V) No. 5 — Chassis ground:
(3V) No. 4 — (3V) No. 5:
Is the resistance 1 MΩ or
more?
Go to step 11. Check the door
harness, and if any
fault is found,
replace the har-
ness. If there is no
fault, replace the
airbag rear har-
ness together with
body harness.
11 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 12. Go to step 15.
12 REPLACE SIDE AIRBAG SENSOR LH AND
CHECK AIRBAG CONTROL MODULE AF-
TER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the side airbag sensor LH. <Ref. to
AB-54, REMOVAL, Side Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 13. Go to step 15.
Step Check Yes No
15WRX_STI_US_EN.book 72 ペー   
AB(diag)-73
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AX:DTC B1650 OCCUPANT CLASSIFICATION SYSTEM MALFUNCTION
NOTE:
Refer to “Occupant Detection System” for details on DTC B1650. <Ref. to OD(diag)-19, DTC B1650 OCCU-
PANT CLASSIFICATION SYSTEM MALFUNCTION, Diagnostic Procedure with Diagnostic Trouble Code
(DTC).>
AY:DTC B1655 FRONT BUCKLE SWITCH RH FAILURE
NOTE:
Refer to “Occupant Detection System” for details on DTC B1655. <Ref. to OD(diag)-21, DTC B1655 FRONT
BUCKLE SWITCH RH FAILURE, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
13 REPLACE CURTAIN AIRBAG SENSOR LH
AND CHECK AIRBAG CONTROL MODULE
AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the curtain airbag sensor LH. <Ref.
to AB-56, REMOVAL, Curtain Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 14. Go to step 15.
14 REPLACE FRONT DOOR IMPACT SENSOR
LH AND CHECK AIRBAG CONTROL MOD-
ULE AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the front door impact sensor LH.
<Ref. to AB-52, REMOVAL, Front Door Impact
Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 15.
15 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Perform the diag-
nosis according to
DTC.
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 73 ペー   
AB(diag)-74
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
AZ:DTC B1660 PASSENGER’S AIRBAG ON INDICATOR FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Passenger’s airbag indicator is faulty.
Airbag control module is faulty.
Airbag main harness circuit is open or shorted.
Body harness circuit is open.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK FOR POOR CONTACT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Check that the connector between the air-
bag control module and MFD is securely con-
nected.
Is there poor contact of any
connector?
Repair the bulk-
head harness. Or
replace the airbag
main harness
along with body
harness.
Go to step 2.
2 CHECK AIRBAG MAIN HARNESS.
1) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
2) Connect the battery ground terminal and
turn the ignition switch to ON.
NOTE:
Neither of ON/OFF illuminates when it is nor-
mal.
Does the passenger’s airbag
indicator illuminate?
Go to step 3. Go to step 4.
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
i230
17
16
218
3
4
5
7
6
14131211
910
15
AB6
i122
1234
5
789
10
6
11 12
B31
23
67
1
589
4
10
6
5
AB1
B31
17
7
B552
i230
10
11
i122
3
MFD
AB6
17
23
AB-03479
AIRBAG CM
PASSENGER'S
AIRBAG ON INDICATOR
PASSENGER'S
AIRBAG OFF INDICATOR
FB-12
F/B FUSE NO. 2
(IG)
15WRX_STI_US_EN.book 74 ペー   
AB(diag)-75
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the MFD and disconnect the con-
nector (i122).
3) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
4) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
5) Measure the resistance between connector
(2AG) in the test harness AG and chassis
ground.
Connector & terminal
(2AG) No. 9 — (2AG) No. 8:
(2AG) No. 9 — Chassis ground:
(2AG) No. 8 — Chassis ground:
Is the resistance 1 MΩ or
more?
Replace the MFD.
<Ref. to IDI-20,
REMOVAL, Multi-
function Display
(MFD).>
Repair the bulk-
head harness. Or
replace the airbag
main harness
along with body
harness.
4 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB6, AB17,
AB18) from the airbag control module, and con-
nect the connector (1AH) in the test harness
AH.
3) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
4) Connect the connectors (7AG) and (8AG) in
the test harness AG.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the passenger’s airbag
indicator illuminate?
Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK AIRBAG MAIN HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the MFD and disconnect the con-
nector (i122).
3) Measure the resistance between connector
(2AG) in the test harness AG and connector
(i122).
Connector & terminal
(2AG) No. 9 — (i122) No. 11:
(2AG) No. 8 — (i122) No. 10:
Is the resistance less than 10
Ω?
Go to step 6. Repair the bulk-
head harness. Or
replace the airbag
main harness
along with body
harness.
6 CHECK BODY HARNESS.
1) Turn the ignition switch to ON.
2) Measure the voltage between connector
(i122) and chassis ground.
Connector & terminal
(i122) No. 3 (+) — Chassis ground (–):
Is the voltage 10 V or more? Replace the MFD.
<Ref. to IDI-20,
REMOVAL, Multi-
function Display
(MFD).>
Check the power
supply circuit of
MFD.
Step Check Yes No
15WRX_STI_US_EN.book 75 ペー   
AB(diag)-76
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BA:DTC B1675 SATELLITE SAFING SENSOR FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Satellite safing sensor is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
BB:DTC B1676 LOST COMMUNICATION WITH SATELLITE SAFING SENSOR
NOTE:
For details on DTC B1676, refer to DTC B1677. <Ref. to AB(diag)-77, DTC B1677 SATELLITE SAFING
SENSOR INITIALIZATION INCOMPLETE, Diagnostic Chart with Trouble Code.>
Step Check Yes No
1 REPLACE SATELLITE SAFING SENSOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the satellite safing sensor with a
genuine sensor. <Ref. to AB-58, REMOVAL,
Satellite Safing Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
15WRX_STI_US_EN.book 76 ペー   
AB(diag)-77
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BC:DTC B1677 SATELLITE SAFING SENSOR INITIALIZATION INCOMPLETE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of satellite safing sensor.
Satellite safing sensor is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
(AB18, AB41) between the airbag control mod-
ule and the satellite safing sensor.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
1524
10
9
1514
67
11 12
3
8
13
AB18
AB-03480
12
AB41
AB41
2
1
15
14
AB18
SATELLITE SAFING
SENSOR
AIRBAG CM
15WRX_STI_US_EN.book 77 ペー   
AB(diag)-78
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SATELLITE SAFING SENSOR).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB21, AB26)
from seat belt pretensioner.
3) Disconnect the connectors (AB31, AB33)
from curtain airbag module.
4) Disconnect connectors (AB19) and (AB24)
from the side airbag module.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
9) Disconnect the connector (AB41) from the
satellite safing sensor and connect to the test
harness H connector (1H).
10) Measure the resistance between connec-
tors (5AG) and (4AG) in the test harness AG
and connector (3H) in the test harness H.
Connector & terminal
(4AG) No. 5 — (3H) No. 5:
(5AG) No. 13 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 3. Replace the airbag
rear harness along
with body harness.
3 CHECK AIRBAG REAR HARNESS (BE-
TWEEN AIRBAG CONTROL MODULE AND
SATELLITE SAFING SENSOR).
Measure the resistance between connector in
the test harness AG and chassis ground, and
the resistance between connector terminals in
the test harness AG.
Connector & terminal
(4AG) No. 5 — Chassis ground:
(5AG) No. 13 — Chassis ground:
(4AG) No. 5 — (5AG) No. 13:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the satel-
lite safing sensor.
<Ref. to AB-58,
REMOVAL, Satel-
lite Safing Sen-
sor.> Replace the
airbag control
module if not oper-
ating normally
even after replac-
ing the sensor.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 5.
Step Check Yes No
15WRX_STI_US_EN.book 78 ペー   
AB(diag)-79
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 79 ペー   
AB(diag)-80
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BD:DTC B16F8 SATELLITE SAFING SENSOR RECOGNITION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Satellite safing sensor is misinstalled.
Airbag control module is faulty.
BE:DTC B16F9 DOOR SENSOR RH RECOGNITION ERROR
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Front door impact sensor RH is misinstalled.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
BF:DTC B1690 DOOR SENSOR RH FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Front door impact sensor RH is faulty.
If DTC B1690 is displayed, the circuit within the front door impact sensor RH is faulty.
Replace the front door impact sensor RH. <Ref. to AB-52, REMOVAL, Front Door Impact Sensor.>
BG:DTC B1692 LOST COMMUNICATION WITH DOOR SENSOR RH
NOTE:
For details on DTC B1692, refer to DTC B1693. <Ref. to AB(diag)-81, DTC B1693 DOOR SENSOR RH INI-
TIALIZATION INCOMPLETE, Diagnostic Chart with Trouble Code.>
Step Check Yes No
1 REPLACE SATELLITE SAFING SENSOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the satellite safing sensor with a
genuine sensor. <Ref. to AB-58, REMOVAL,
Satellite Safing Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Step Check Yes No
1 REPLACE FRONT DOOR IMPACT SENSOR
RH.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the front door impact sensor RH
with a genuine sensor. <Ref. to AB-52,
REMOVAL, Front Door Impact Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
15WRX_STI_US_EN.book 80 ペー   
AB(diag)-81
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BH:DTC B1693 DOOR SENSOR RH INITIALIZATION INCOMPLETE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of side sensor bus RH.
Front door impact sensor RH is faulty.
Curtain airbag sensor RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1622 or B1623 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 2.
2 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1632 or B1633 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 3.
3 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the front
door impact sensor RH.
Is there poor contact? Replace the airbag
rear harness and
the door harness.
Go to step 4.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
10
9
6
7
11
8
AB33
2
1
12
AB33
AB18
AB28
AB34
31
2
4
31
2
4
AB24
AB64
2
1
AB24
3
2
4
3
2
1
AB28
AB-03477
AIRBAG CM
CURTAIN
AIRBAG
SENSOR RH
SIDE
AIRBAG
MODULE RH
SIDE
AIRBAG
SENSOR RH
CURTAIN
AIRBAG
MODULE RH
FRONT
DOOR IMPACT
SENSOR RH
15WRX_STI_US_EN.book 81 ペー   
AB(diag)-82
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
4 CHECK AIRBAG REAR HARNESS AND
DOOR HARNESS (BETWEEN CURTAIN AIR-
BAG SENSOR RH AND DOOR SENSOR RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the connector (AB24) from side
airbag module RH.
5) Disconnect the connector (AB34) from cur-
tain airbag sensor (RH), and connect the con-
nector (2V) in test harness V to connector
(AB34).
6) Disconnect the connector (AB64) from the
front door impact sensor RH, and connect the
connector (1H) in the test harness H to connec-
tor (AB64).
7) Measure the resistance between connector
(3V) in the test harness V and connector (3H) in
the test harness H.
Connector & terminal
(3V) No. 4 — (3H) No. 5:
(3V) No. 5 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 5. Check the door
harness, and if any
fault is found,
replace the har-
ness. If there is no
fault, replace the
airbag rear har-
ness together with
body harness.
5 CHECK AIRBAG REAR HARNESS AND
DOOR HARNESS (BETWEEN CURTAIN AIR-
BAG SENSOR RH AND DOOR SENSOR RH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) termi-
nals in test harness V.
Connector & terminal
(3V) No. 4 — Chassis ground:
(3V) No. 5 — Chassis ground:
(3V) No. 4 — (3V) No. 5:
Is the resistance 1 MΩ or
more?
Go to step 6. Check the door
harness, and if any
fault is found,
replace the har-
ness. If there is no
fault, replace the
airbag rear har-
ness together with
body harness.
6 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 7. Go to step 9.
7 REPLACE FRONT DOOR IMPACT SENSOR
RH AND CHECK AIRBAG CONTROL MOD-
ULE AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the front door impact sensor RH.
<Ref. to AB-52, REMOVAL, Front Door Impact
Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 8. Go to step 9.
Step Check Yes No
15WRX_STI_US_EN.book 82 ペー   
AB(diag)-83
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
8 REPLACE CURTAIN AIRBAG SENSOR RH
AND CHECK AIRBAG CONTROL MODULE
AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the curtain airbag sensor RH.
<Ref. to AB-56, REMOVAL, Curtain Airbag
Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 9.
9 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code”.
<Ref. to AB(diag)-
33, LIST, List of
Diagnostic Trouble
Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 83 ペー   
AB(diag)-84
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BI: DTC B16FA LOST COMMUNICATION WITH DOOR SENSOR LH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Front door impact sensor LH is misinstalled.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
BJ:DTC B1695 DOOR SENSOR LH FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Front door impact sensor LH is faulty.
If DTC AB is displayed, the circuit within the front door impact sensor LH is faulty.
Replace the front door impact sensor LH. <Ref. to AB-52, REMOVAL, Front Door Impact Sensor.>
BK:DTC B1697 LOST COMMUNICATION WITH DOOR SENSOR LH
NOTE:
Refer to DTC B1697 for details on DTC B1698. <Ref. to AB(diag)-85, DTC B1698 DOOR SENSOR LH INI-
TIALIZATION INCOMPLETE, Diagnostic Chart with Trouble Code.>
Step Check Yes No
1 REPLACE FRONT DOOR IMPACT SENSOR
LH.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the front door impact sensor LH
with a genuine sensor. <Ref. to AB-52,
REMOVAL, Front Door Impact Sensor.>
Does the warning light go off? Finish the diagno-
sis.
Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
15WRX_STI_US_EN.book 84 ペー   
AB(diag)-85
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BL:DTC B1698 DOOR SENSOR LH INITIALIZATION INCOMPLETE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Open or short circuit in harness of side sensor bus LH.
Front door impact sensor LH is faulty.
Curtain airbag sensor LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1627 or B1628 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 2.
2 CHECK DTC.
Read the DTC. (Current malfunction)
Is DTC B1637 or B1638 dis-
played?
Perform the diag-
nosis according to
DTC.
Go to step 3.
3 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the front
door impact sensor LH.
Is there poor contact? Replace the airbag
rear harness and
the door harness.
Go to step 4.
AB17
13
8
3
1211
76
14 15
9
10
4251
12
AB62AB58
1
2
12
AB31
AB23
AB32
31
2
4
31
2
4
AB19
1
2
AB62 R123
4
3
2
1
AB32
6
7
9
10
15
8
AB31
2
1
AB17
AB58
2
1
AB19
2
3
4
3
2
1
AB23
AB-03478
AIRBAG CM
CURTAIN
AIRBAG
SENSOR LH
SIDE
AIRBAG
MODULE LH
SIDE
AIRBAG
SENSOR LH
CURTAIN
AIRBAG
MODULE LH
FRONT
DOOR IMPACT
SENSOR LH
15WRX_STI_US_EN.book 85 ペー   
AB(diag)-86
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
4 CHECK AIRBAG REAR HARNESS AND
DOOR HARNESS (BETWEEN CURTAIN AIR-
BAG SENSOR LH AND FRONT DOOR IM-
PACT SENSOR LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB31) from cur-
tain airbag module LH.
4) Disconnect the connector (AB19) from side
airbag module LH.
5) Disconnect the connector (AB32) from cur-
tain airbag sensor LH, and connect the connec-
tor (2V) in test harness V to connector (AB32).
6) Disconnect the connector (AB58) from the
front door impact sensor LH, and connect the
connector (1H) in the test harness H to connec-
tor (AB58).
7) Measure the resistance between connector
(3V) in the test harness V and connector (3H) in
the test harness H.
Connector & terminal
(3V) No. 4 — (3H) No. 5:
(3V) No. 5 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 5. Check the door
harness, and if any
fault is found,
replace the har-
ness. If there is no
fault, replace the
airbag rear har-
ness together with
body harness.
5 CHECK AIRBAG REAR HARNESS AND
DOOR HARNESS (BETWEEN CURTAIN AIR-
BAG SENSOR LH AND FRONT DOOR IM-
PACT SENSOR LH).
Measure the resistance between connector
(3V) in test harness V and chassis ground, and
the resistance between connector (3V) termi-
nals in test harness V.
Connector & terminal
(3V) No. 4 — Chassis ground:
(3V) No. 5 — Chassis ground:
(3V) No. 4 — (3V) No. 5:
Is the resistance 1 MΩ or
more?
Go to step 6. Check the door
harness, and if any
fault is found,
replace the har-
ness. If there is no
fault, replace the
airbag rear har-
ness together with
body harness.
6 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 7. Go to step 9.
7 REPLACE FRONT DOOR IMPACT SENSOR
LH AND CHECK AIRBAG CONTROL MOD-
ULE AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the front door impact sensor LH.
<Ref. to AB-52, REMOVAL, Front Door Impact
Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Go to step 8. Go to step 9.
Step Check Yes No
15WRX_STI_US_EN.book 86 ペー   
AB(diag)-87
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
8 REPLACE CURTAIN AIRBAG SENSOR LH
AND CHECK AIRBAG CONTROL MODULE
AFTER REPLACEMENT.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Replace the curtain airbag sensor LH. <Ref.
to AB-56, REMOVAL, Curtain Airbag Sensor.>
3) Connect all connectors.
4) Clear the memory.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 9.
9 CHECK FOR ANY OTHER DTC ON DISPLAY.
Read the DTC. (Current malfunction)
Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code”.
<Ref. to AB(diag)-
33, LIST, List of
Diagnostic Trouble
Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 87 ペー   
AB(diag)-88
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BM:DTC B161A LOST COMMUNICATION WITH FRONT SATELLITE SENSOR
BUS
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Harness between airbag control module and front sub sensor is open or shorted.
Front sub sensor is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the front
sub sensor.
Is there poor contact? Replace the airbag
main harness
along with body
harness.
Go to step 2.
12
AB16
AB13
AB6
1234567
8
9
10
11 12 13 14
15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
29
27
30
28
AB6
AB16
AB13
1
2
1
2
AB-02835
AIRBAG CM
FRONT SUB
SENSOR LH
FRONT SUB
SENSOR RH
15WRX_STI_US_EN.book 88 ペー   
AB(diag)-89
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tors (AB7) and (AB2).
3) Remove the console front panel and discon-
nect the connector (AB9).
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
6) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
7) Disconnect the connector (AB13) from the
front sub sensor LH, and then connect the con-
nector (1H) in the test harness H to connector
(AB13).
8) Measure the resistance between connector
(4AG) in the test harness AG and connector
(3H) in the test harness H.
Connector & terminal
(4AG) No. 7 — (3H) No. 5:
(4AG) No. 9 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS LH).
Measure the resistance between connector
(4AG) in the test harness AG and chassis
ground, and the resistance between connector
(4AG) terminals in the test harness AG.
Connector & terminal
(4AG) No. 7 — Chassis ground:
(4AG) No. 9 — Chassis ground:
(4AG) No. 7 — (4AG) No. 9:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS RH).
1) Disconnect the connector (AB16) from the
front sub sensor RH, and then connect the con-
nector (1H) in the test harness H to connector
(AB16).
2) Measure the resistance between connector
(4AG) in the test harness AG and connector
(3H) in the test harness H.
Connector & terminal
(4AG) No. 14 — (3H) No. 5:
(4AG) No. 12 — (3H) No. 6:
Is the resistance less than 10
Ω?
Go to step 5. Replace the airbag
main harness
along with body
harness.
5 CHECK AIRBAG MAIN HARNESS (FRONT
SENSOR BUS RH).
Measure the resistance between connector
(4AG) in the test harness AG and chassis
ground, and the resistance between connector
(4AG) terminals in the test harness AG.
Connector & terminal
(4AG) No. 12 — Chassis ground:
(4AG) No. 14 — Chassis ground:
(4AG) No. 12 — (4AG) No. 14:
Is the resistance 1 MΩ or
more?
Go to step 6. Replace the airbag
rear harness along
with body harness.
Step Check Yes No
15WRX_STI_US_EN.book 89 ペー   
AB(diag)-90
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
6 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the front
sub sensor LH and
front sub sensor
RH. <Ref. to AB-
50, REMOVAL,
Front Sub Sen-
sor.> Replace the
airbag control
module if not oper-
ating normally
even after replac-
ing the sensor.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 7.
7 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code”.
<Ref. to AB(diag)-
33, List of Diagnos-
tic Trouble Code
(DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 90 ペー   
AB(diag)-91
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BN:DTC B16F1 PASSENGER’S SEAT BELT WARNING FAILURE
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag control module is faulty.
Meter is faulty.
Harness circuits between meter and airbag control module are open, shorted or shorted to ground.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK AIRBAG HARNESS.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
3) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the passenger’s seat belt
warning light blink for 6 sec-
onds and go off?
Go to step 3. Go to step 2.
2 CHECK AIRBAG HARNESS.
1) Turn the ignition switch to OFF.
2) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
3) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
4) Measure the resistance between connector
(2AG) in the test harness AG and chassis
ground.
Connector & terminal
(2AG) No. 10 — Chassis ground:
Is the resistance 1 MΩ or
more?
Replace the meter.
<Ref. to IDI-13,
REMOVAL, Com-
bination Meter.>
Repair the bulk-
head harness and
instrument panel
harness. Or
replace the airbag
main harness
along with body
harness.
i10
11 12
9
10
7856341
2
15 1613 14 19
18
20
21 22 23 24 26
25
27 28 29 30 31 32 33 34 35 36 37 38 39 40
17
i230
17
16
218
3
4
5
7
6
14131211
910
15
B31
23
67
1
589
4
10
AB6
1234567
8
9
10
11 12 13 14
15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
7
B31
AB1
16
i10
i230
B552
16
AB6
15
AB-03481
AIRBAG CM
COMBINATION METER
15WRX_STI_US_EN.book 91 ペー   
AB(diag)-92
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BO:DTC B16F0 PASSENGER’S AIRBAG OFF INDICATOR FAILURE
NOTE:
For details on DTC B16F0, refer to DTC B1660. <Ref. to AB(diag)-74, DTC B1660 PASSENGER’S AIRBAG
ON INDICATOR FAILURE, Diagnostic Chart with Trouble Code.>
BP:DTC B1760 SENSOR MAT ABNORMAL
NOTE:
Refer to “Occupant Detection System” for details on DTC B1760. <Ref. to OD(diag)-22, DTC B1760 SEN-
SOR MAT ABNORMAL, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
BQ:DTC B1761 SENSOR MAT LIQUID COATING ABNORMAL
NOTE:
Refer to “Occupant Detection System” for details on DTC B1761. <Ref. to OD(diag)-23, DTC B1761 SEN-
SOR MAT LIQUID COATING ABNORMAL, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
BR:DTC B1771 BUCKLE SWITCH ABNORMAL
NOTE:
Refer to “Occupant Detection System” for details on DTC B1771. <Ref. to OD(diag)-23, DTC B1771 BUCK-
LE SWITCH ABNORMAL, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
BS:DTC B1795 ECU INTERNAL CIRCUIT FAULT
NOTE:
Refer to “Occupant Detection System” for details on DTC B1795. <Ref. to OD(diag)-23, DTC B1795 ECU IN-
TERNAL CIRCUIT FAULT, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
3 CHECK AIRBAG HARNESS.
1) Turn the ignition switch to OFF.
2) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
3) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
4) Connect the connectors (7AG) and (8AG) in
the test harness AG.
5) Turn the ignition switch to ON.
Does the passenger’s seat belt
warning light blink for 6 sec-
onds, then repeatedly light and
go off?
Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 4.
4 CHECK AIRBAG HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors (7AG) and
(8AG) in the test harness AG in the condition of
step 3.
3) Disconnect the connector (i10) from meter.
4) Measure the resistance between connector
(2AG) in the test harness AG and connector
(i84).
Connector & terminal
(2AG) No. 10 — (i10) No. 16:
Is the resistance less than 10
Ω?
Replace the meter.
<Ref. to IDI-13,
REMOVAL, Com-
bination Meter.>
Repair the bulk-
head harness and
instrument panel
harness. Or
replace the airbag
main harness
along with body
harness.
Step Check Yes No
15WRX_STI_US_EN.book 92 ペー   
AB(diag)-93
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BT:DTC B1800 SHORT IN DRIVER’S AIRBAG
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted.
Airbag module harness (driver’s side) circuit is shorted.
Roll connector circuit is shorted.
Driver’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
NOTE:
Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
driver’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK DRIVER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the driver’s airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB38).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the connector (1Q) in the test har-
ness Q to connector (AB37).
6) Connect the airbag resistor to the connector
(2Q) in the test harness Q.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the
driver’s airbag
module. <Ref. to
AB-33, Driver’s Air-
bag Module.>
Go to step 3.
1212
B:A:
AB6
B1
B2
5
6
AB2
AB7
2
1
A2
A1
7
8
4
3
AB37
A:
AB38
B:
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
AB2
3
4
12
AB6
AB37 AB38
AB-03482
ROLL CONNECTOR
DRIVER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 93 ペー   
AB(diag)-94
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK ROLL CONNECTOR AND AIRBAG
MAIN HARNESS (DRIVER’S AIRBAG HAR-
NESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the console front panel and discon-
nect the connector (AB9).
3) Disconnect the driver’s knee airbag module
connector (AB66).
4) Disconnect the airbag resistor from the con-
nector (2N) in test harness N and from the con-
nector (2Q) in test harness Q.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(2Q) terminals in test harness Q.
Connector & terminal
(2Q) No. 1 — (2Q) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 5. Go to step 4.
4 CHECK AIRBAG MAIN HARNESS (DRIV-
ER’S AIRBAG HARNESS).
1) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
2) Measure the resistance between connector
(3AG) terminals in test harness AG.
Connector & terminal
(3AG) No. 1 — (3AG) No. 3:
Is the resistance 1 MΩ or
more?
Replace the roll
connector. <Ref. to
AB-60, Roll Con-
nector.>
Replace the airbag
main harness
along with body
harness.
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 6.
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 94 ペー   
AB(diag)-95
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BU:DTC B1801 OPEN IN DRIVER’S AIRBAG
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is open.
Airbag module harness (driver’s side) circuit is open.
Roll connector is open.
Driver’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
NOTE:
Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
driver’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK DRIVER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the driver’s airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB38).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the connector (1Q) in the test har-
ness Q to connector (AB37).
6) Connect the airbag resistor to the connector
(2Q) in the test harness Q.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the
driver’s airbag
module. <Ref. to
AB-33, Driver’s Air-
bag Module.>
Go to step 3.
1212
B:A:
AB6
B1
B2
5
6
AB2
AB7
2
1
A2
A1
7
8
4
3
AB37
A:
AB38
B:
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
AB2
3
4
12
AB6
AB37 AB38
AB-03482
ROLL CONNECTOR
DRIVER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 95 ペー   
AB(diag)-96
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK ROLL CONNECTOR AND AIRBAG
MAIN HARNESS (DRIVER’S AIRBAG HAR-
NESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the console front panel and discon-
nect the connector (AB9).
3) Disconnect the driver’s knee airbag module
connector (AB66).
4) Disconnect the airbag resistor from the con-
nector (2N) in test harness N.
5) Disconnect the airbag resistor from the con-
nector (2Q) of test harness Q.
6) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
7) Measure the resistance between connector
(2Q) terminals in test harness Q.
Connector & terminal
(2Q) No. 1 — (2Q) No. 2:
Is the resistance less than 10
Ω?
Go to step 5. Go to step 4.
4 CHECK ROLL CONNECTOR.
1) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
2) Measure the resistance between connector
(2Q) terminals in test harness Q.
Connector & terminal
(2Q) No. 1 — (2Q) No. 2:
Is the resistance less than 10
Ω?
Replace the airbag
main harness
along with body
harness.
Replace the roll
connector. <Ref. to
AB-60, Roll Con-
nector.>
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 6.
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 96 ペー   
AB(diag)-97
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BV:DTC B1802 SHORT IN DRIVER’S AIRBAG (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to ground.
Airbag module harness (driver’s side) circuit is shorted to ground.
Roll connector circuit is shorted to ground.
Driver’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
NOTE:
Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
driver’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK DRIVER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the driver’s airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB38).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the connector (1Q) in the test har-
ness Q to connector (AB37).
6) Connect the airbag resistor to the connector
(2Q) in the test harness Q.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the
driver’s airbag
module. <Ref. to
AB-33, Driver’s Air-
bag Module.>
Go to step 3.
1212
B:A:
AB6
B1
B2
5
6
AB2
AB7
2
1
A2
A1
7
8
4
3
AB37
A:
AB38
B:
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
AB2
3
4
12
AB6
AB37 AB38
AB-03482
ROLL CONNECTOR
DRIVER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 97 ペー   
AB(diag)-98
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK ROLL CONNECTOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
3) Disconnect the driver’s knee airbag module
connector (AB66).
4) Disconnect the airbag resistor from the con-
nector (2N) in test harness N and from the con-
nector (2Q) in test harness Q.
5) Measure the resistance between connector
(2Q) in the test harness Q and chassis ground.
Connector & terminal
(2Q) No. 1 — Chassis ground:
(2Q) No. 2 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the roll
connector. <Ref. to
AB-60, Roll Con-
nector.>
4 CHECK AIRBAG MAIN HARNESS (DRIV-
ER’S AIRBAG HARNESS).
1) Disconnect the test harness N from connec-
tor (AB38).
2) Disconnect the test harness Q from connec-
tor (AB37).
3) Remove the console front panel and discon-
nect the connector (AB9).
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
6) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
7) Measure the resistance between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 1 — Chassis ground:
(3AG) No. 3 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 5. Replace the airbag
main harness
along with body
harness.
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 6.
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 98 ペー   
AB(diag)-99
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BW:DTC B1803 SHORT IN DRIVER’S AIRBAG (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to power supply.
Airbag module harness (driver’s side) circuit is shorted to power supply.
Roll connector circuit is shorted to power supply.
Driver’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
NOTE:
Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
driver’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK DRIVER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the driver’s airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB38).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the connector (1Q) in the test har-
ness Q to connector (AB37).
6) Connect the airbag resistor to the connector
(2Q) in the test harness Q.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the
driver’s airbag
module. <Ref. to
AB-33, Driver’s Air-
bag Module.>
Go to step 3.
1212
B:A:
AB6
B1
B2
5
6
AB2
AB7
2
1
A2
A1
7
8
4
3
AB37
A:
AB38
B:
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
AB2
3
4
12
AB6
AB37 AB38
AB-03482
ROLL CONNECTOR
DRIVER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 99 ペー   
AB(diag)-100
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK ROLL CONNECTOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
3) Disconnect the driver’s knee airbag module
connector (AB66).
4) Disconnect the airbag resistor from the con-
nector (2N) in test harness N and from the con-
nector (2Q) in test harness Q.
5) Measure the voltage between connector
(2Q) in the test harness Q and chassis ground.
Connector & terminal
(2Q) No. 1 (+) — Chassis ground (–):
(2Q) No. 2 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the roll
connector. <Ref. to
AB-60, Roll Con-
nector.>
4 CHECK AIRBAG MAIN HARNESS (DRIV-
ER’S AIRBAG HARNESS).
1) Disconnect the test harness N from connec-
tor (AB38).
2) Disconnect the test harness Q from connec-
tor (AB37).
3) Remove the console front panel and discon-
nect the connector (AB9).
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
6) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
8) Measure the voltage between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 1 (+) — Chassis ground (–):
(3AG) No. 3 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 5. Replace the airbag
main harness
along with body
harness.
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 6.
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 100 ージ 20  
AB(diag)-101
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BX:DTC B1805 SHORT IN PASSENGER’S AIRBAG
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted.
Airbag module harness circuit (passenger’s side) is shorted.
Passenger’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the pas-
senger’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
AB6
18 19 20
21 22 23 24 25 26 27 28
123 5678
10
94
11 12 13 14 16 1715
29 30
AB6
4
3
AB9
1
2
1
2
3
4
AB9
1234
AB-03369
PASSENGER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 101 ージ 20  
AB(diag)-102
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (PASSEN-
GER’S AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB7) and
(AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the connectors (AB6, AB17,
AB18) from the airbag control module, connect
the connector (1AH) in the test harness AH, and
release the short mechanism of the connectors
(AB6, AB17, AB18).
5) Disconnect the passenger’s airbag module
connector (AB9).
6) Using a probe, measure the resistance
between the terminals of connector (AB9).
<Ref. to AB(diag)-16, HOW TO USE PROBE,
PREPARATION TOOL, General Description.>
CAUTION:
When measuring the resistance, make sure
that the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 1 — (AB9) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG CONTROL MODULE.
1) Disconnect the test harness AG or test har-
ness AH from the connectors (AB6, AB17,
AB18).
2) Connect the connectors (AB6, AB17, AB18)
and the airbag control module.
3) Connect the connectors (AB7) and (AB2).
4) Connect the connector (AB66) to the
driver’s knee airbag module.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
6) Perform the Inspection Mode.
7) Read the DTC. (Current malfunction)
Is DTC B1805 displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 4.
4 CHECK PASSENGER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Connect the passenger’s airbag module
connector (AB9).
3) Connect the battery ground terminal and
turn the ignition switch to ON.
4) Perform the Inspection Mode.
5) Read the DTC. (Current malfunction)
Is DTC B1805 displayed? Replace the pas-
senger’s airbag
module. <Ref. to
AB-36, REMOVAL,
Passenger’s Air-
bag Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 102 ージ 20  
AB(diag)-103
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BY:DTC B1806 OPEN IN PASSENGER’S AIRBAG
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is open.
Airbag module harness (passenger’s side) circuit is open.
Passenger’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the pas-
senger’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
AB6
18 19 20
21 22 23 24 25 26 27 28
123 5678
10
94
11 12 13 14 16 1715
29 30
AB6
4
3
AB9
1
2
1
2
3
4
AB9
1234
AB-03369
PASSENGER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 103 ージ 20  
AB(diag)-104
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (PASSEN-
GER’S AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB7) and
(AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Disconnect the passenger’s airbag module
connector (AB9).
6) Using a probe, measure the resistance
between the terminals of connector (AB9).
<Ref. to AB(diag)-16, HOW TO USE PROBE,
PREPARATION TOOL, General Description.>
CAUTION:
When measuring the resistance, make sure
that the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 1 — (AB9) No. 2:
Is the resistance less than 10
Ω?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG CONTROL MODULE.
1) Connect the connectors (AB6, AB17, AB18)
and the airbag control module.
2) Connect the connectors (AB7) and (AB2).
3) Connect the connector (AB66) to the
driver’s knee airbag module.
4) Using a probe, short the terminals No. 1 and
No. 2 of connector (AB9). <Ref. to AB(diag)-16,
HOW TO USE PROBE, PREPARATION TOOL,
General Description.>
CAUTION:
When shorting the terminals, make sure that
the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 1 — (AB9) No. 2:
5) Connect the battery ground terminal and
turn the ignition switch to ON.
6) Perform the Inspection Mode.
7) Read the DTC. (Current malfunction)
Is DTC B1806 displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 4.
4 CHECK PASSENGER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Connect the passenger’s airbag module
connector (AB9).
3) Connect the battery negative terminal, and
clear the memory.
4) Perform the Inspection Mode.
5) Read the DTC. (Current malfunction)
Is DTC B1806 displayed? Replace the pas-
senger’s airbag
module. <Ref. to
AB-36, REMOVAL,
Passenger’s Air-
bag Module.>
Go to step 5.
Step Check Yes No
15WRX_STI_US_EN.book 104 ージ 20  
AB(diag)-105
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 105 ージ 20  
AB(diag)-106
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
BZ:DTC B1807 SHORT IN PASSENGER’S AIRBAG (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to ground.
Airbag module harness (passenger’s side) circuit is shorted to ground.
Passenger’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the pas-
senger’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
AB6
18 19 20
21 22 23 24 25 26 27 28
123 5678
10
94
11 12 13 14 16 1715
29 30
AB6
4
3
AB9
1
2
1
2
3
4
AB9
1234
AB-03369
PASSENGER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 106 ージ 20  
AB(diag)-107
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (PASSEN-
GER’S AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB7) and
(AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Disconnect the passenger’s airbag module
connector (AB9).
6) Using a probe, measure the resistance
between the connector (AB9) and chassis
ground. <Ref. to AB(diag)-16, HOW TO USE
PROBE, PREPARATION TOOL, General
Description.>
CAUTION:
When measuring the resistance, make sure
that the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 1 — Chassis ground:
(AB9) No. 2 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG CONTROL MODULE.
1) Connect the connectors (AB6, AB17, AB18)
and the airbag control module.
2) Using a probe, short the terminals No. 1 and
No. 2 of connector (AB9). <Ref. to AB(diag)-16,
HOW TO USE PROBE, PREPARATION TOOL,
General Description.>
CAUTION:
When shorting the terminals, make sure that
the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 1 — (AB9) No. 2:
3) Connect the battery ground terminal and
turn the ignition switch to ON.
4) Perform the Inspection Mode.
5) Read the DTC. (Current malfunction)
Is DTC B1807 displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 4.
4 CHECK PASSENGER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Release the short circuit of connector
(AB9).
3) Connect the passenger’s airbag module
connector (AB9).
4) Connect the connectors (AB7) and (AB2).
5) Connect the connector (AB66) to the
driver’s knee airbag module.
6) Connect the battery ground terminal and
turn the ignition switch to ON.
7) Perform the Inspection Mode.
8) Read the DTC. (Current malfunction)
Is DTC B1807 displayed? Replace the pas-
senger’s airbag
module. <Ref. to
AB-36, REMOVAL,
Passenger’s Air-
bag Module.>
Go to step 5.
Step Check Yes No
15WRX_STI_US_EN.book 107 ージ 20  
AB(diag)-108
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 108 ージ 20  
AB(diag)-109
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CA:DTC B1808 SHORT IN PASSENGER’S AIRBAG (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to power supply.
Airbag module harness (passenger’s side) circuit is shorted to power supply.
Passenger’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the pas-
senger’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
AB6
18 19 20
21 22 23 24 25 26 27 28
123 5678
10
94
11 12 13 14 16 1715
29 30
AB6
4
3
AB9
1
2
1
2
3
4
AB9
1234
AB-03369
PASSENGER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 109 ージ 20  
AB(diag)-110
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (PASSEN-
GER’S AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB7) and
(AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Disconnect the passenger’s airbag module
connector (AB9).
6) Using a probe, measure the voltage
between the connector (AB9) and chassis
ground. <Ref. to AB(diag)-16, HOW TO USE
PROBE, PREPARATION TOOL, General
Description.>
CAUTION:
When measuring the voltage, make sure
that the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 1 (+) — Chassis ground (–):
(AB9) No. 2 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG CONTROL MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Connect the connectors (AB6, AB17, AB18)
and the airbag control module.
3) Using a probe, short the terminals No. 1 and
No. 2 of connector (AB9). <Ref. to AB(diag)-16,
HOW TO USE PROBE, PREPARATION TOOL,
General Description.>
CAUTION:
When shorting the terminals, make sure that
the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 1 — (AB9) No. 2:
4) Connect the battery ground terminal and
turn the ignition switch to ON.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is DTC B1808 displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 4.
Step Check Yes No
15WRX_STI_US_EN.book 110 ージ 20  
AB(diag)-111
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
4 CHECK PASSENGER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Release the short circuit of connector
(AB9).
3) Connect the passenger’s airbag module
connector (AB9).
4) Connect the connectors (AB7) and (AB2).
5) Connect the connector (AB66) to the
driver’s knee airbag module.
6) Connect the battery ground terminal and
turn the ignition switch to ON.
7) Perform the Inspection Mode.
8) Read the DTC. (Current malfunction)
Is DTC B1808 displayed? Replace the pas-
senger’s airbag
module. <Ref. to
AB-36, REMOVAL,
Passenger’s Air-
bag Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 111 ージ 20  
AB(diag)-112
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CB:DTC B1810 SHORT IN DRIVER’S AIRBAG DUAL STAGE - 2ND STEP
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted.
Airbag module harness (driver’s side) circuit is shorted.
Roll connector circuit is shorted.
Driver’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
NOTE:
Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
driver’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK DRIVER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the driver’s airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB38).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the connector (1Q) in the test har-
ness Q to connector (AB37).
6) Connect the airbag resistor to the connector
(2Q) in the test harness Q.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the
driver’s airbag
module. <Ref. to
AB-33, Driver’s Air-
bag Module.>
Go to step 3.
1212
B:A:
AB6
B1
B2
5
6
AB2
AB7
2
1
A2
A1
7
8
4
3
AB37
A:
AB38
B:
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
AB2
3
4
12
AB6
AB37 AB38
AB-03482
ROLL CONNECTOR
DRIVER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 112 ージ 20  
AB(diag)-113
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK ROLL CONNECTOR AND AIRBAG
MAIN HARNESS (DRIVER’S AIRBAG HAR-
NESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the console front panel and discon-
nect the connector (AB9).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the airbag resistor from the con-
nector (2N) in test harness N and from the con-
nector (2Q) in test harness Q.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(2N) terminals in test harness N.
Connector & terminal
(2N) No. 1 — (2N) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 5. Go to step 4.
4 CHECK AIRBAG MAIN HARNESS (DRIV-
ER’S AIRBAG HARNESS).
1) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
2) Disconnect the test harness Q from connec-
tor (AB37).
3) Measure the resistance between connector
(3AG) terminals in test harness AG.
Connector & terminal
(3AG) No. 2 — (3AG) No. 4:
Is the resistance 1 MΩ or
more?
Replace the roll
connector. <Ref. to
AB-60, Roll Con-
nector.>
Replace the airbag
main harness
along with body
harness.
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 6.
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 113 ージ 20  
AB(diag)-114
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CC:DTC B1811 OPEN IN DRIVER’S AIRBAG DUAL STAGE - 2ND STEP
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is open.
Airbag module harness (driver’s side) circuit is open.
Roll connector circuit is open.
Driver’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
NOTE:
Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
driver’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK DRIVER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the driver’s airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB38).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the connector (1Q) in the test har-
ness Q to connector (AB37).
6) Connect the airbag resistor to the connector
(2Q) in the test harness Q.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the
driver’s airbag
module. <Ref. to
AB-33, Driver’s Air-
bag Module.>
Go to step 3.
1212
B:A:
AB6
B1
B2
5
6
AB2
AB7
2
1
A2
A1
7
8
4
3
AB37
A:
AB38
B:
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
AB2
3
4
12
AB6
AB37 AB38
AB-03482
ROLL CONNECTOR
DRIVER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 114 ージ 20  
AB(diag)-115
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK ROLL CONNECTOR AND AIRBAG
MAIN HARNESS (DRIVER’S AIRBAG HAR-
NESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the console front panel and discon-
nect the connector (AB9).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the airbag resistor from the con-
nector (2N) in test harness N.
5) Disconnect the airbag resistor from the con-
nector (2Q) of test harness Q.
6) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
7) Measure the resistance between connector
(2N) terminals in test harness N.
Connector & terminal
(2N) No. 1 — (2N) No. 2:
Is the resistance less than 10
Ω?
Go to step 5. Go to step 4.
4 CHECK ROLL CONNECTOR.
1) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
2) Measure the resistance between connector
(2N) terminals in test harness N.
Connector & terminal
(2N) No. 1 — (2N) No. 2:
Is the resistance less than 10
Ω?
Replace the airbag
main harness
along with body
harness.
Replace the roll
connector. <Ref. to
AB-60, Roll Con-
nector.>
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 6.
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 115 ージ 20  
AB(diag)-116
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CD:DTC B1812 SHORT IN DRIVER’S AIRBAG DUAL STAGE - 2ND STEP (TO
GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to ground.
Airbag module harness (driver’s side) circuit is shorted to ground.
Roll connector circuit is shorted to ground.
Driver’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
NOTE:
Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
driver’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
1212
B:A:
AB6
B1
B2
5
6
AB2
AB7
2
1
A2
A1
7
8
4
3
AB37
A:
AB38
B:
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
AB2
3
4
12
AB6
AB37 AB38
AB-03482
ROLL CONNECTOR
DRIVER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 116 ージ 20  
AB(diag)-117
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK DRIVER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the driver’s airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB38).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the connector (1Q) in the test har-
ness Q to connector (AB37).
6) Connect the airbag resistor to the connector
(2Q) in the test harness Q.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the
driver’s airbag
module. <Ref. to
AB-33, Driver’s Air-
bag Module.>
Go to step 3.
3 CHECK ROLL CONNECTOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the airbag resistor from the con-
nector (2N) in test harness N and from the con-
nector (2Q) in test harness Q.
5) Measure the resistance between connector
(2N) in the test harness N and chassis ground.
Connector & terminal
(2N) No. 1 — Chassis ground:
(2N) No. 2 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the roll
connector. <Ref. to
AB-60, Roll Con-
nector.>
4 CHECK AIRBAG MAIN HARNESS (DRIV-
ER’S AIRBAG HARNESS).
1) Disconnect the test harness N from connec-
tor (AB38).
2) Disconnect the test harness Q from connec-
tor (AB37).
3) Remove the console front panel and discon-
nect the connector (AB9).
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
6) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
7) Measure the resistance between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 2 — Chassis ground:
(3AG) No. 4 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 5. Replace the airbag
main harness
along with body
harness.
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 6.
Step Check Yes No
15WRX_STI_US_EN.book 117 ージ 20  
AB(diag)-118
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 118 ージ 20  
AB(diag)-119
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CE:DTC B1813 SHORT IN DRIVER’S AIRBAG DUAL STAGE - 2ND STEP CIR-
CUIT (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to power supply.
Airbag module harness (driver’s side) circuit is shorted to power supply.
Roll connector is shorted to power supply.
Driver’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
NOTE:
Prior to starting work, prepare two AIRBAG RESISTORs (98299PA040).
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
driver’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
1212
B:A:
AB6
B1
B2
5
6
AB2
AB7
2
1
A2
A1
7
8
4
3
AB37
A:
AB38
B:
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
AB2
3
4
12
AB6
AB37 AB38
AB-03482
ROLL CONNECTOR
DRIVER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 119 ージ 20  
AB(diag)-120
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK DRIVER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the driver’s airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB38).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the connector (1Q) in the test har-
ness Q to connector (AB37).
6) Connect the airbag resistor to the connector
(2Q) in the test harness Q.
7) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the
driver’s airbag
module. <Ref. to
AB-33, Driver’s Air-
bag Module.>
Go to step 3.
3 CHECK ROLL CONNECTOR.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the airbag resistor from the con-
nector (2N) in test harness N and from the con-
nector (2Q) in test harness Q.
5) Measure the voltage between connector
(2N) in the test harness N and chassis ground.
Connector & terminal
(2N) No. 1 (+) — Chassis ground (–):
(2N) No. 2 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the roll
connector. <Ref. to
AB-60, Roll Con-
nector.>
4 CHECK AIRBAG MAIN HARNESS (DRIV-
ER’S AIRBAG HARNESS).
1) Disconnect the test harness N from connec-
tor (AB38).
2) Disconnect the test harness Q from connec-
tor (AB37).
3) Remove the console front panel and discon-
nect the connector (AB9).
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
6) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
7) Measure the voltage between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 2 (+) — Chassis ground (–):
(3AG) No. 4 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 5. Replace the airbag
main harness
along with body
harness.
5 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 6.
Step Check Yes No
15WRX_STI_US_EN.book 120 ージ 20  
AB(diag)-121
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
6 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 121 ージ 20  
AB(diag)-122
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CF:DTC B1815 OPEN IN PASSENGER’S AIRBAG DUAL STAGE - 2ND STEP
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted.
Airbag module harness circuit (passenger’s side) is shorted.
Passenger’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the pas-
senger’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
AB6
18 19 20
21 22 23 24 25 26 27 28
123 5678
10
94
11 12 13 14 16 1715
29 30
AB6
4
3
AB9
1
2
1
2
3
4
AB9
1234
AB-03369
PASSENGER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 122 ージ 20  
AB(diag)-123
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (PASSEN-
GER’S AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB7) and
(AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the connectors (AB6, AB17,
AB18) from the airbag control module, connect
the connector (1AH) in the test harness AH, and
release the short mechanism of the connectors
(AB6, AB17, AB18).
5) Disconnect the passenger’s airbag module
connector (AB9).
6) Using a probe, measure the resistance
between the terminals of connector (AB9).
<Ref. to AB(diag)-16, HOW TO USE PROBE,
PREPARATION TOOL, General Description.>
CAUTION:
When measuring the resistance, make sure
that the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 3 — (AB9) No. 4:
Is the resistance 1 MΩ or
more?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG CONTROL MODULE.
1) Disconnect the test harness AG and test
harness AH from the connectors (AB6, AB17,
AB18).
2) Connect the connectors (AB6, AB17, AB18)
and the airbag control module.
3) Connect the connectors (AB7) and (AB2).
4) Connect the connector (AB66) to the
driver’s knee airbag module.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
6) Perform the Inspection Mode.
7) Read the DTC. (Current malfunction)
Is DTC B1815 displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 4.
4 CHECK PASSENGER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Connect the passenger’s airbag module
connector (AB9).
3) Connect the battery ground terminal and
turn the ignition switch to ON.
4) Perform the Inspection Mode.
5) Read the DTC. (Current malfunction)
Is DTC B1815 displayed? Replace the pas-
senger’s airbag
module. <Ref. to
AB-36, REMOVAL,
Passenger’s Air-
bag Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 123 ージ 20  
AB(diag)-124
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CG:DTC B1816 OPEN IN PASSENGER’S AIRBAG DUAL STAGE - 2ND STEP
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is open.
Airbag module harness (passenger’s side) circuit is open.
Passenger’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the pas-
senger’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
AB6
18 19 20
21 22 23 24 25 26 27 28
123 5678
10
94
11 12 13 14 16 1715
29 30
AB6
4
3
AB9
1
2
1
2
3
4
AB9
1234
AB-03369
PASSENGER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 124 ージ 20  
AB(diag)-125
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (PASSEN-
GER’S AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB7) and
(AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Disconnect the passenger’s airbag module
connector (AB9).
6) Using a probe, measure the resistance
between the terminals of connector (AB9).
<Ref. to AB(diag)-16, HOW TO USE PROBE,
PREPARATION TOOL, General Description.>
CAUTION:
When measuring the resistance, make sure
that the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 3 — (AB9) No. 4:
Is the resistance less than 10
Ω?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG CONTROL MODULE.
1) Connect the connectors (AB6, AB17, AB18)
and the airbag control module.
2) Connect the connectors (AB7) and (AB2).
3) Connect the connector (AB66) to the
driver’s knee airbag module.
4) Using a probe, short the terminals No. 3 and
No. 4 of connector (AB9). <Ref. to AB(diag)-16,
HOW TO USE PROBE, PREPARATION TOOL,
General Description.>
CAUTION:
When shorting the terminals, make sure that
the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 3 — (AB9) No. 4:
5) Connect the battery ground terminal and
turn the ignition switch to ON.
6) Perform the Inspection Mode.
7) Read the DTC. (Current malfunction)
Is DTC B1816 displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 4.
4 CHECK PASSENGER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Connect the passenger’s airbag module
connector (AB9).
3) Connect the battery ground terminal and
turn the ignition switch to ON.
4) Perform the Inspection Mode.
5) Read the DTC. (Current malfunction)
Is DTC B1816 displayed? Replace the pas-
senger’s airbag
module. <Ref. to
AB-36, REMOVAL,
Passenger’s Air-
bag Module.>
Go to step 5.
Step Check Yes No
15WRX_STI_US_EN.book 125 ージ 20  
AB(diag)-126
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 126 ージ 20  
AB(diag)-127
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CH:DTC B1817 SHORT IN PASSENGER’S AIRBAG DUAL STAGE - 2ND STEP
(TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to ground.
Airbag module harness (passenger’s side) circuit is shorted to ground.
Passenger’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the pas-
senger’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
AB6
18 19 20
21 22 23 24 25 26 27 28
123 5678
10
94
11 12 13 14 16 1715
29 30
AB6
4
3
AB9
1
2
1
2
3
4
AB9
1234
AB-03369
PASSENGER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 127 ージ 20  
AB(diag)-128
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (PASSEN-
GER’S AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB7) and
(AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Disconnect the passenger’s airbag module
connector (AB9).
6) Using a probe, measure the resistance
between the connector (AB9) and chassis
ground. <Ref. to AB(diag)-16, HOW TO USE
PROBE, PREPARATION TOOL, General
Description.>
CAUTION:
When measuring the resistance, make sure
that the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 3 — Chassis ground:
(AB9) No. 4 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG CONTROL MODULE.
1) Connect the connectors (AB6, AB17, AB18)
and the airbag control module.
2) Using a probe, short the terminals No. 3 and
No. 4 of connector (AB9). <Ref. to AB(diag)-16,
HOW TO USE PROBE, PREPARATION TOOL,
General Description.>
CAUTION:
When shorting the terminals, make sure that
the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 3 — (AB9) No. 4:
3) Connect the battery ground terminal and
turn the ignition switch to ON.
4) Perform the Inspection Mode.
5) Read the DTC. (Current malfunction)
Is DTC B1817 displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 4.
4 CHECK PASSENGER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Release the short circuit of connector
(AB9).
3) Connect the passenger’s airbag module
connector (AB9).
4) Connect the connectors (AB7) and (AB2).
5) Connect the connector (AB66) to the
driver’s knee airbag module.
6) Connect the battery ground terminal and
turn the ignition switch to ON.
7) Perform the Inspection Mode.
8) Read the DTC. (Current malfunction)
Is DTC B1817 displayed? Replace the pas-
senger’s airbag
module. <Ref. to
AB-36, REMOVAL,
Passenger’s Air-
bag Module.>
Go to step 5.
Step Check Yes No
15WRX_STI_US_EN.book 128 ージ 20  
AB(diag)-129
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 129 ージ 20  
AB(diag)-130
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CI: DTC B1818 SHORT IN PASSENGER’S AIRBAG DUAL STAGE - 2ND STEP
CIRCUIT (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to power supply.
Airbag module harness (passenger’s side) circuit is shorted to power supply.
Passenger’s airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the pas-
senger’s airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
AB6
18 19 20
21 22 23 24 25 26 27 28
123 5678
10
94
11 12 13 14 16 1715
29 30
AB6
4
3
AB9
1
2
1
2
3
4
AB9
1234
AB-03369
PASSENGER'S AIRBAG MODULE
AIRBAG CM
15WRX_STI_US_EN.book 130 ージ 20  
AB(diag)-131
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
2 CHECK AIRBAG MAIN HARNESS (PASSEN-
GER’S AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connectors (AB7) and
(AB2).
3) Disconnect the connector (AB66) from the
driver’s knee airbag module.
4) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
5) Disconnect the passenger’s airbag module
connector (AB9).
6) Using a probe, measure the voltage
between the connector (AB9) and chassis
ground. <Ref. to AB(diag)-16, HOW TO USE
PROBE, PREPARATION TOOL, General
Description.>
CAUTION:
When measuring the voltage, make sure
that the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 3 (+) — Chassis ground (–):
(AB9) No. 4 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 3. Replace the airbag
main harness
along with body
harness.
3 CHECK AIRBAG CONTROL MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Connect the connectors (AB6, AB17, AB18)
and the airbag control module.
3) Using a probe, short the terminals No. 3 and
No. 4 of connector (AB9). <Ref. to AB(diag)-16,
HOW TO USE PROBE, PREPARATION TOOL,
General Description.>
CAUTION:
When shorting the terminals, make sure that
the probe is inserted from the back side
(harness side) of the connector. Also, do not
insert the probe forcibly.
Connector & terminal
(AB9) No. 3 — (AB9) No. 4:
4) Connect the battery ground terminal and
turn the ignition switch to ON.
5) Perform the Inspection Mode.
6) Read the DTC. (Current malfunction)
Is DTC B1818 displayed? Replace the airbag
control module.
<Ref. to AB-48,
REMOVAL, Airbag
Control Module.>
Go to step 4.
Step Check Yes No
15WRX_STI_US_EN.book 131 ージ 20  
AB(diag)-132
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
4 CHECK PASSENGER’S AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Release the short circuit of connector
(AB9).
3) Connect the passenger’s airbag module
connector (AB9).
4) Connect the connectors (AB7) and (AB2).
5) Connect the connector (AB66) to the
driver’s knee airbag module.
6) Connect the battery ground terminal and
turn the ignition switch to ON.
7) Perform the Inspection Mode.
8) Read the DTC. (Current malfunction)
Is DTC B1818 displayed? Replace the pas-
senger’s airbag
module. <Ref. to
AB-36, REMOVAL,
Passenger’s Air-
bag Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 132 ージ 20  
AB(diag)-133
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CJ:DTC B1820 SHORT IN SIDE AIRBAG RH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag harness RH circuit is shorted.
Side airbag module RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, side airbag
module RH and the side airbag sensor RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB24) from the
side airbag module RH, and connect the con-
nector (1AJ) in the test harness AJ to connector
(AB24).
3) Connect the airbag resistor to the test har-
ness AJ connector (3AJ).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the side
airbag module RH.
<Ref. to AB-43,
REMOVAL, Side
Airbag Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
6
7
11
8
AB18
AB28
AB34
31
2
4
31
2
4
AB24
AB64
2
1
AB24
3
2
4
3
2
1
AB28
AB-03483
AIRBAG CM
CURTAIN AIRBAG
SENSOR RH
SIDE AIRBAG
MODULE RH
SIDE AIRBAG
SENSOR RH
FRONT DOOR
IMPACT SENSOR RH
15WRX_STI_US_EN.book 133 ージ 20  
AB(diag)-134
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the airbag resistor from test har-
ness AJ.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AJ) in the test harness AJ and chassis
ground.
Connector & terminal
(3AJ) No. 1 — (3AJ) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 134 ージ 20  
AB(diag)-135
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CK:DTC B1821 OPEN IN SIDE AIRBAG RH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag harness RH circuit is open.
Side airbag module RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, side airbag
module RH and the side airbag sensor RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB24) from the
side airbag module RH, and connect the con-
nector (1AJ) in the test harness AJ to connector
(AB24).
3) Connect the airbag resistor to the test har-
ness AJ connector (3AJ).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the side
airbag module RH.
<Ref. to AB-43,
REMOVAL, Side
Airbag Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
6
7
11
8
AB18
AB28
AB34
31
2
4
31
2
4
AB24
AB64
2
1
AB24
3
2
4
3
2
1
AB28
AB-03483
AIRBAG CM
CURTAIN AIRBAG
SENSOR RH
SIDE AIRBAG
MODULE RH
SIDE AIRBAG
SENSOR RH
FRONT DOOR
IMPACT SENSOR RH
15WRX_STI_US_EN.book 135 ージ 20  
AB(diag)-136
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the airbag resistor from test har-
ness AJ.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
in the test harness AG and connector in the test
harness AJ.
Connector & terminal
(4AG) No. 11 — (3AJ) No. 1:
(4AG) No. 13 — (3AJ) No. 2:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 136 ージ 20  
AB(diag)-137
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CL:DTC B1822 SHORT IN SIDE AIRBAG RH (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag harness RH circuit is shorted to ground.
Side airbag module RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, side airbag
module RH and the side airbag sensor RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB24), and con-
nect the connector (1AJ) in test harness AJ to
connector (AB24).
3) Connect the airbag resistor to the test har-
ness AJ connector (3AJ).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the side
airbag module RH.
<Ref. to AB-43,
REMOVAL, Side
Airbag Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
6
7
11
8
AB18
AB28
AB34
31
2
4
31
2
4
AB24
AB64
2
1
AB24
3
2
4
3
2
1
AB28
AB-03483
AIRBAG CM
CURTAIN AIRBAG
SENSOR RH
SIDE AIRBAG
MODULE RH
SIDE AIRBAG
SENSOR RH
FRONT DOOR
IMPACT SENSOR RH
15WRX_STI_US_EN.book 137 ージ 20  
AB(diag)-138
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the airbag resistor from test har-
ness AJ.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AJ) in the test harness AJ and chassis
ground.
Connector & terminal
(3AJ) No. 1 — Chassis ground:
(3AJ) No. 2 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 138 ージ 20  
AB(diag)-139
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CM:DTC B1823 SHORT IN SIDE AIRBAG RH (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag harness RH is shorted to power supply.
Side airbag module RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, side airbag
module RH and the side airbag sensor RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB24), and con-
nect the connector (1AJ) in test harness AJ to
connector (AB24).
3) Connect the airbag resistor to the test har-
ness AJ connector (3AJ).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the side
airbag module RH.
<Ref. to AB-43,
REMOVAL, Side
Airbag Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
6
7
11
8
AB18
AB28
AB34
31
2
4
31
2
4
AB24
AB64
2
1
AB24
3
2
4
3
2
1
AB28
AB-03483
AIRBAG CM
CURTAIN AIRBAG
SENSOR RH
SIDE AIRBAG
MODULE RH
SIDE AIRBAG
SENSOR RH
FRONT DOOR
IMPACT SENSOR RH
15WRX_STI_US_EN.book 139 ージ 20  
AB(diag)-140
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the airbag resistor from test har-
ness.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Connect the battery ground terminal and
turn the ignition switch to ON.
9) Measure the voltage between connector
(3AJ) in the test harness AJ and chassis
ground.
Connector & terminal
(3AJ) No. 1 (+) — Chassis ground (–):
(3AJ) No. 2 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 140 ージ 20  
AB(diag)-141
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CN:DTC B1825 SHORT IN SIDE AIRBAG LH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag harness LH circuit is shorted.
Side airbag module LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, side airbag
module LH and the side airbag sensor LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB19) from the
side airbag module LH, and connect the con-
nector (1AJ) in test harness AJ to the connector
(AB19).
3) Connect the airbag resistor to the test har-
ness AJ connector (3AJ).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the side
airbag module LH.
<Ref. to AB-43,
REMOVAL, Side
Airbag Module.>
Go to step 3.
AB17
13
8
3
1211
76
14 15
9
10
4251
12
AB62AB58
1
2
AB23
AB32
31
2
4
31
2
4
AB19
1
2
AB62 R123
4
3
2
1
AB32
9
10
15
8
AB17
AB58
2
1
AB19
2
3
4
3
2
1
AB23
AB-03484
AIRBAG CM
CURTAIN AIRBAG
SENSOR LH
SIDE AIRBAG
MODULE LH
SIDE AIRBAG
SENSOR LH
FRONT DOOR
IMPACT SENSOR LH
15WRX_STI_US_EN.book 141 ージ 20  
AB(diag)-142
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG MODULE HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB31) from cur-
tain airbag module LH.
4) Disconnect the airbag resistor from test har-
ness AJ.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AJ) terminals in test harness AJ.
Connector & terminal
(3AJ) No. 1 — (3AJ) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 142 ージ 20  
AB(diag)-143
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CO:DTC B1826 OPEN IN SIDE AIRBAG LH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag harness LH circuit is open.
Side airbag module LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, side airbag
module LH and the side airbag sensor LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB19) from the
side airbag module LH, and connect the con-
nector (1AJ) in test harness AJ to the connector
(AB19).
3) Connect the airbag resistor to the test har-
ness AJ connector (3AJ).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the side
airbag module LH.
<Ref. to AB-43,
REMOVAL, Side
Airbag Module.>
Go to step 3.
AB17
13
8
3
1211
76
14 15
9
10
4251
12
AB62AB58
1
2
AB23
AB32
31
2
4
31
2
4
AB19
1
2
AB62 R123
4
3
2
1
AB32
9
10
15
8
AB17
AB58
2
1
AB19
2
3
4
3
2
1
AB23
AB-03484
AIRBAG CM
CURTAIN AIRBAG
SENSOR LH
SIDE AIRBAG
MODULE LH
SIDE AIRBAG
SENSOR LH
FRONT DOOR
IMPACT SENSOR LH
15WRX_STI_US_EN.book 143 ージ 20  
AB(diag)-144
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG MODULE HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB31) from cur-
tain airbag module LH.
4) Disconnect the airbag resistor from test har-
ness AJ.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(4AG) or (5AG) in the test harness AG and con-
nector (3AJ) in the test harness AJ.
Connector & terminal
(4AG) No. 8 — (3AJ) No. 2:
(4AG) No. 10 — (3AJ) No. 1:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 144 ージ 20  
AB(diag)-145
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CP:DTC B1827 SHORT IN SIDE AIRBAG LH (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag harness LH circuit is shorted to ground.
Side airbag module LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, side airbag
module LH and the side airbag sensor LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB19), and con-
nect the connector (1AJ) in test harness AJ to
connector (AB19).
3) Connect the airbag resistor to the test har-
ness AJ connector (3AJ).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the side
airbag module LH.
<Ref. to AB-43,
REMOVAL, Side
Airbag Module.>
Go to step 3.
AB17
13
8
3
1211
76
14 15
9
10
4251
12
AB62AB58
1
2
AB23
AB32
31
2
4
31
2
4
AB19
1
2
AB62 R123
4
3
2
1
AB32
9
10
15
8
AB17
AB58
2
1
AB19
2
3
4
3
2
1
AB23
AB-03484
AIRBAG CM
CURTAIN AIRBAG
SENSOR LH
SIDE AIRBAG
MODULE LH
SIDE AIRBAG
SENSOR LH
FRONT DOOR
IMPACT SENSOR LH
15WRX_STI_US_EN.book 145 ージ 20  
AB(diag)-146
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG MODULE HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB31) from cur-
tain airbag module LH.
4) Disconnect the airbag resistor from test har-
ness.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AJ) in the test harness AJ and chassis
ground.
Connector & terminal
(3AJ) No. 1 — Chassis ground:
(3AJ) No. 2 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 146 ージ 20  
AB(diag)-147
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CQ:DTC B1828 SHORT IN SIDE AIRBAG LH (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Side airbag harness LH is shorted to power supply.
Side airbag module LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, side airbag
module LH and the side airbag sensor LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB19), and con-
nect the connector (1AJ) in test harness AJ to
connector (AB19).
3) Connect the airbag resistor to the test har-
ness AJ connector (3AJ).
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the side
airbag module LH.
<Ref. to AB-43,
REMOVAL, Side
Airbag Module.>
Go to step 3.
AB17
13
8
3
1211
76
14 15
9
10
4251
12
AB62AB58
1
2
AB23
AB32
31
2
4
31
2
4
AB19
1
2
AB62 R123
4
3
2
1
AB32
9
10
15
8
AB17
AB58
2
1
AB19
2
3
4
3
2
1
AB23
AB-03484
AIRBAG CM
CURTAIN AIRBAG
SENSOR LH
SIDE AIRBAG
MODULE LH
SIDE AIRBAG
SENSOR LH
FRONT DOOR
IMPACT SENSOR LH
15WRX_STI_US_EN.book 147 ージ 20  
AB(diag)-148
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG MODULE HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB31) from cur-
tain airbag module LH.
4) Disconnect the airbag resistor from test har-
ness.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Connect the battery ground terminal and
turn the ignition switch to ON.
9) Measure the voltage between connector
(3AJ) in the test harness AJ and chassis
ground.
Connector & terminal
(3AJ) No. 1 (+) — Chassis ground (–):
(3AJ) No. 2 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 148 ージ 20  
AB(diag)-149
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CR:DTC B1830 SHORT IN CURTAIN AIRBAG RH SQUIB CIRCUIT
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag harness RH circuit is shorted.
Curtain airbag module RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, curtain air-
bag module RH and the curtain airbag sensor
RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK CURTAIN AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB33) from cur-
tain airbag module RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB33).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the cur-
tain airbag module
RH. <Ref. to AB-
46, Curtain Airbag
Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
10
9
11
8
AB33
2
1
12
AB33
AB18
AB28
AB34
31
2
4
AB64
2
1
4
3
2
1
AB28
AB-03485
AIRBAG CM
CURTAIN AIRBAG
SENSOR RH
SIDE AIRBAG
SENSOR RH
CURTAIN AIRBAG
MODULE RH
FRONT DOOR
IMPACT SENSOR RH
15WRX_STI_US_EN.book 149 ージ 20  
AB(diag)-150
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (CUR-
TAIN AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB24) from side
airbag module RH.
4) Disconnect the airbag resistor from test har-
ness N.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(2N) terminals in test harness N.
Connector & terminal
(2N) No. 1 — (2N) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 150 ージ 20  
AB(diag)-151
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CS:DTC B1831 OPEN IN CURTAIN AIRBAG RH SQUIB CIRCUIT
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag harness RH circuit is open.
Curtain airbag module RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, curtain air-
bag module RH and the curtain airbag sensor
RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK CURTAIN AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB33) from cur-
tain airbag module RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB33).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the cur-
tain airbag module
RH. <Ref. to AB-
46, Curtain Airbag
Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
10
9
11
8
AB33
2
1
12
AB33
AB18
AB28
AB34
31
2
4
AB64
2
1
4
3
2
1
AB28
AB-03485
AIRBAG CM
CURTAIN AIRBAG
SENSOR RH
SIDE AIRBAG
SENSOR RH
CURTAIN AIRBAG
MODULE RH
FRONT DOOR
IMPACT SENSOR RH
15WRX_STI_US_EN.book 151 ージ 20  
AB(diag)-152
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (CUR-
TAIN AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB24) from side
airbag module RH.
4) Disconnect the airbag resistor from test har-
ness N.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(5AG) or (6AG) in the test harness AG and con-
nector (2N) in the test harness N.
Connector & terminal
(5AG) No. 6 — (2N) No. 2:
(5AG) No. 12 — (2N) No. 1:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 152 ージ 20  
AB(diag)-153
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CT:DTC B1832 SHORT IN CURTAIN AIRBAG RH SQUIB CIRCUIT (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag harness RH circuit is shorted to ground.
Curtain airbag module RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, curtain air-
bag module RH and the curtain airbag sensor
RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK CURTAIN AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB33), and con-
nect the connector (1N) in test harness N to
connector (AB33).
3) Connect the airbag resistor to the connector
(2N) of test harness N.
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the cur-
tain airbag module
RH. <Ref. to AB-
46, Curtain Airbag
Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
10
9
11
8
AB33
2
1
12
AB33
AB18
AB28
AB34
31
2
4
AB64
2
1
4
3
2
1
AB28
AB-03485
AIRBAG CM
CURTAIN AIRBAG
SENSOR RH
SIDE AIRBAG
SENSOR RH
CURTAIN AIRBAG
MODULE RH
FRONT DOOR
IMPACT SENSOR RH
15WRX_STI_US_EN.book 153 ージ 20  
AB(diag)-154
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (CUR-
TAIN AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB24) from side
airbag module RH.
4) Disconnect the airbag resistor from test har-
ness N.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(2N) in the test harness N and chassis ground.
Connector & terminal
(2N) No. 1 — Chassis ground:
(2N) No. 2 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 154 ージ 20  
AB(diag)-155
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CU:DTC B1833 SHORT IN CURTAIN SHIELD AIRBAG RH SQUIB CIRCUIT (TO
+B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag harness RH is shorted to power supply.
Curtain airbag module RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, curtain air-
bag module RH and the curtain airbag sensor
RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK CURTAIN AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB33), and con-
nect the connector (1N) in test harness N to
connector (AB33).
3) Connect the airbag resistor to the connector
(2N) of test harness N.
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the cur-
tain airbag module
RH. <Ref. to AB-
46, Curtain Airbag
Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
1
2
AB63 R124
12
AB63AB64
1
2
4
3
2
1
AB34
10
9
11
8
AB33
2
1
12
AB33
AB18
AB28
AB34
31
2
4
AB64
2
1
4
3
2
1
AB28
AB-03485
AIRBAG CM
CURTAIN AIRBAG
SENSOR RH
SIDE AIRBAG
SENSOR RH
CURTAIN AIRBAG
MODULE RH
FRONT DOOR
IMPACT SENSOR RH
15WRX_STI_US_EN.book 155 ージ 20  
AB(diag)-156
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (CUR-
TAIN AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Disconnect the connector (AB24) from side
airbag module RH.
4) Disconnect the airbag resistor from test har-
ness N.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Connect the battery ground terminal and
turn the ignition switch to ON.
9) Measure the voltage between connector
(2N) in the test harness N and chassis ground.
Connector & terminal
(2N) No. 1 (+) — Chassis ground (–):
(2N) No. 2 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 156 ージ 20  
AB(diag)-157
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CV:DTC B1835 SHORT IN CURTAIN AIRBAG LH SQUIB CIRCUIT
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag harness LH circuit is shorted.
Curtain airbag module LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, curtain air-
bag module LH and the curtain airbag sensor
LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK CURTAIN AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB31) from cur-
tain airbag module LH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB31).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the cur-
tain airbag module
LH. <Ref. to AB-
46, Curtain Airbag
Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB17
12
AB62AB58
1
2
12
AB31
AB23
AB32
31
2
4
1
2
AB62 R123
4
3
2
1
AB32
6
7
15
8
AB31
2
1
AB17
AB58
2
1
4
3
2
1
AB23
AB-03486
AIRBAG CM
CURTAIN AIRBAG
SENSOR LH
SIDE AIRBAG
SENSOR LH
CURTAIN AIRBAG
MODULE LH
FRONT DOOR
IMPACT SENSOR LH
15WRX_STI_US_EN.book 157 ージ 20  
AB(diag)-158
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (CUR-
TAIN AIRBAG MODULE HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB19) from side
airbag module LH.
4) Disconnect the airbag resistor from test har-
ness N.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(2N) terminals in test harness N.
Connector & terminal
(2N) No. 1 — (2N) No. 2:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 158 ージ 20  
AB(diag)-159
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CW:DTC B1836 OPEN IN CURTAIN AIRBAG LH SQUIB CIRCUIT
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag harness LH circuit is open.
Curtain airbag module LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, curtain air-
bag module LH and the curtain airbag sensor
LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK CURTAIN AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB31) from cur-
tain airbag module LH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB31).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the cur-
tain airbag module
LH. <Ref. to AB-
46, Curtain Airbag
Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB17
12
AB62AB58
1
2
12
AB31
AB23
AB32
31
2
4
1
2
AB62 R123
4
3
2
1
AB32
6
7
15
8
AB31
2
1
AB17
AB58
2
1
4
3
2
1
AB23
AB-03486
AIRBAG CM
CURTAIN AIRBAG
SENSOR LH
SIDE AIRBAG
SENSOR LH
CURTAIN AIRBAG
MODULE LH
FRONT DOOR
IMPACT SENSOR LH
15WRX_STI_US_EN.book 159 ージ 20  
AB(diag)-160
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (CUR-
TAIN AIRBAG MODULE HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB19) from side
airbag module LH.
4) Disconnect the airbag resistor from test har-
ness N.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(5AG) or (6AG) in the test harness AG and con-
nector (2N) in the test harness N.
Connector & terminal
(5AG) No. 2 — (2N) No. 2:
(5AG) No. 4 — (2N) No. 1:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 160 ージ 20  
AB(diag)-161
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CX:DTC B1837 SHORT IN CURTAIN AIRBAG LH SQUIB CIRCUIT (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag harness LH circuit is shorted to ground.
Curtain airbag module LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, curtain air-
bag module LH and the curtain airbag sensor
LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK CURTAIN AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB31), and con-
nect the connector (1N) in test harness N to
connector (AB31).
3) Connect the airbag resistor to the connector
(2N) of test harness N.
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the cur-
tain airbag module
LH. <Ref. to AB-
46, Curtain Airbag
Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB17
12
AB62AB58
1
2
12
AB31
AB23
AB32
31
2
4
1
2
AB62 R123
4
3
2
1
AB32
6
7
15
8
AB31
2
1
AB17
AB58
2
1
4
3
2
1
AB23
AB-03486
AIRBAG CM
CURTAIN AIRBAG
SENSOR LH
SIDE AIRBAG
SENSOR LH
CURTAIN AIRBAG
MODULE LH
FRONT DOOR
IMPACT SENSOR LH
15WRX_STI_US_EN.book 161 ージ 20  
AB(diag)-162
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (CUR-
TAIN AIRBAG MODULE HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB19) from side
airbag module LH.
4) Disconnect the airbag resistor from test har-
ness N.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(2N) in the test harness N and chassis ground.
Connector & terminal
(2N) No. 1 — Chassis ground:
(2N) No. 2 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 162 ージ 20  
AB(diag)-163
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CY:DTC B1838 SHORT IN CURTAIN SHIELD AIRBAG LH SQUIB CIRCUIT (TO
+B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Curtain airbag harness LH is shorted to power supply.
Curtain airbag module LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module, curtain air-
bag module LH and the curtain airbag sensor
LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK CURTAIN AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB31), and con-
nect the connector (1N) in test harness N to
connector (AB31).
3) Connect the airbag resistor to the connector
(2N) of test harness N.
4) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the cur-
tain airbag module
LH. <Ref. to AB-
46, Curtain Airbag
Module.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB17
12
AB62AB58
1
2
12
AB31
AB23
AB32
31
2
4
1
2
AB62 R123
4
3
2
1
AB32
6
7
15
8
AB31
2
1
AB17
AB58
2
1
4
3
2
1
AB23
AB-03486
AIRBAG CM
CURTAIN AIRBAG
SENSOR LH
SIDE AIRBAG
SENSOR LH
CURTAIN AIRBAG
MODULE LH
FRONT DOOR
IMPACT SENSOR LH
15WRX_STI_US_EN.book 163 ージ 20  
AB(diag)-164
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (CUR-
TAIN AIRBAG MODULE HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Disconnect the connector (AB19) from side
airbag module LH.
4) Disconnect the airbag resistor from test har-
ness N.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Connect the battery ground terminal and
turn the ignition switch to ON.
9) Measure the voltage between connector
(2N) in the test harness N and chassis ground.
Connector & terminal
(2N) No. 1 (+) — Chassis ground (–):
(2N) No. 2 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 164 ージ 20  
AB(diag)-165
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
CZ:DTC B1860 SHORT IN DRIVER’S KNEE AIRBAG
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted.
Knee airbag module harness circuit is shorted.
Knee airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
knee airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK KNEE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB66) from knee
airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB66).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the knee
airbag module.
<Ref. to AB-35,
REMOVAL, Knee
Airbag Module.>
Go to step 3.
AB6
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
12
AB66
10
9
AB66
2
1
AB6
AB-03077
AIRBAG CM
DRIVER'S
KNEE AIRBAG
MODULE
15WRX_STI_US_EN.book 165 ージ 20  
AB(diag)-166
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG MAIN HARNESS (KNEE
AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
4) Remove the console front panel and discon-
nect the connector (AB9).
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) terminals in test harness AG.
Connector & terminal
(3AG) No. 14 — (3AG) No. 16:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
main harness
along with body
harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 166 ージ 20  
AB(diag)-167
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DA:DTC B1861 OPEN IN DRIVER’S KNEE AIRBAG
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is open.
Knee airbag module harness circuit is open.
Knee airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
knee airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK KNEE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB66) from knee
airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB66).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the knee
airbag module.
<Ref. to AB-35,
REMOVAL, Knee
Airbag Module.>
Go to step 3.
AB6
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
12
AB66
10
9
AB66
2
1
AB6
AB-03077
AIRBAG CM
DRIVER'S
KNEE AIRBAG
MODULE
15WRX_STI_US_EN.book 167 ージ 20  
AB(diag)-168
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG MAIN HARNESS (KNEE
AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
4) Remove the console front panel and discon-
nect the connector (AB9).
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) in the test harness AG and connector
(2N) in the test harness N.
Connector & terminal
(3AG) No. 14 — (2N) No. 2:
(3AG) No. 16 — (2N) No. 1:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
main harness
along with body
harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 168 ージ 20  
AB(diag)-169
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DB:DTC B1862 SHORT IN DRIVER’S KNEE AIRBAG (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to ground.
Knee airbag module harness circuit is shorted to ground.
Knee airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
knee airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK KNEE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB66) from knee
airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB66).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the knee
airbag module.
<Ref. to AB-35,
REMOVAL, Knee
Airbag Module.>
Go to step 3.
AB6
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
12
AB66
10
9
AB66
2
1
AB6
AB-03077
AIRBAG CM
DRIVER'S
KNEE AIRBAG
MODULE
15WRX_STI_US_EN.book 169 ージ 20  
AB(diag)-170
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG MAIN HARNESS (KNEE
AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
4) Remove the console front panel and discon-
nect the connector (AB9).
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 14 — Chassis ground:
(3AG) No. 16 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
main harness
along with body
harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 170 ージ 20  
AB(diag)-171
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DC:DTC B1863 SHORT IN DRIVER’S KNEE AIRBAG (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Airbag main harness circuit is shorted to power supply.
Knee airbag module harness circuit is shorted to power supply.
Knee airbag module is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the
knee airbag module.
Is there poor contact? Replace the airbag
harness.
Go to step 2.
2 CHECK KNEE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB66) from knee
airbag module.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB66).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the knee
airbag module.
<Ref. to AB-35,
REMOVAL, Knee
Airbag Module.>
Go to step 3.
AB6
18 19 20
10
21 22 23 24 25 26 27 28
1234
11 12 13 14 16 1715
29 30
56789
12
AB66
10
9
AB66
2
1
AB6
AB-03077
AIRBAG CM
DRIVER'S
KNEE AIRBAG
MODULE
15WRX_STI_US_EN.book 171 ージ 20  
AB(diag)-172
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG MAIN HARNESS (KNEE
AIRBAG HARNESS).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Remove the instrument panel lower cover
and column cover, and disconnect the connec-
tor (AB7) from (AB2).
4) Remove the console front panel and discon-
nect the connector (AB9).
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Connect the battery ground terminal and
turn the ignition switch to ON.
9) Measure the voltage between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 14 (+) — Chassis ground (–):
(3AG) No. 16 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the airbag
main harness
along with body
harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 172 ージ 20  
AB(diag)-173
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DD:DTC B1900 SHORT IN FRONT P/T RH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Seat belt pretensioner RH circuit is shorted.
Pretensioner RH is faulty.
Pretensioner harness RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the seat
belt pretensioner RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB26).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the seat
belt pretensioner
RH. <Ref. to SB-
16, Front Seat
Belt.>
Go to step 3.
12
AB26
1524
10
9
1514
67
11 12
3
8
13
AB18
4
5
AB26
2
1
AB18
AB-03487
AIRBAG CM
PRETENSIONER RH
15WRX_STI_US_EN.book 173 ージ 20  
AB(diag)-174
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (PRE-
TENSIONER HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Disconnect the connector (AB24) from side
airbag module RH.
4) Disconnect the connector (AB33) from cur-
tain airbag module RH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) terminals in test harness AG.
Connector & terminal
(3AG) No. 18 — (3AG) No. 20:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 174 ージ 20  
AB(diag)-175
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DE:DTC B1901 OPEN IN FRONT P/T RH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Seat belt pretensioner RH circuit is open.
Pretensioner RH is faulty.
Pretensioner harness RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the seat
belt pretensioner RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB26).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the seat
belt pretensioner
RH. <Ref. to SB-
16, Front Seat
Belt.>
Go to step 3.
12
AB26
1524
10
9
1514
67
11 12
3
8
13
AB18
4
5
AB26
2
1
AB18
AB-03487
AIRBAG CM
PRETENSIONER RH
15WRX_STI_US_EN.book 175 ージ 20  
AB(diag)-176
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (PRE-
TENSIONER HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from the con-
nector (2N) of test harness N.
3) Disconnect the connector (AB24) from side
airbag module RH.
4) Disconnect the connector (AB33) from cur-
tain airbag module RH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) in the test harness AG and connector
(2N) in the test harness N.
Connector & terminal
(3AG) No. 18 — (2N) No. 2:
(3AG) No. 20 — (2N) No. 1:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 176 ージ 20  
AB(diag)-177
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DF:DTC B1902 SHORT IN FRONT P/T RH (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Seat belt pretensioner RH circuit is shorted to ground.
Pretensioner RH is faulty.
Pretensioner harness RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the seat
belt pretensioner RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB26).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the seat
belt pretensioner
RH. <Ref. to SB-
16, Front Seat
Belt.>
Go to step 3.
12
AB26
1524
10
9
1514
67
11 12
3
8
13
AB18
4
5
AB26
2
1
AB18
AB-03487
AIRBAG CM
PRETENSIONER RH
15WRX_STI_US_EN.book 177 ージ 20  
AB(diag)-178
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (PRE-
TENSIONER HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from the con-
nector (2N) of test harness N.
3) Disconnect the connector (AB24) from side
airbag module RH.
4) Disconnect the connector (AB33) from cur-
tain airbag module RH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 18 — Chassis ground:
(3AG) No. 20 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 178 ージ 20  
AB(diag)-179
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DG:DTC B1903 SHORT IN FRONT P/T RH (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Seat belt pretensioner RH circuit is shorted to power supply.
Pretensioner RH is faulty.
Pretensioner harness RH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the seat
belt pretensioner RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB26) from seat
belt pretensioner RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB26).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the seat
belt pretensioner
RH. <Ref. to SB-
16, Front Seat
Belt.>
Go to step 3.
12
AB26
1524
10
9
1514
67
11 12
3
8
13
AB18
4
5
AB26
2
1
AB18
AB-03487
AIRBAG CM
PRETENSIONER RH
15WRX_STI_US_EN.book 179 ージ 20  
AB(diag)-180
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (PRE-
TENSIONER HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from the con-
nector (2N) of test harness N.
3) Disconnect the connector (AB24) from side
airbag module RH.
4) Disconnect the connector (AB33) from cur-
tain airbag module RH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Connect the battery ground terminal and
turn the ignition switch to ON.
9) Measure the voltage between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 20 (+) — Chassis ground (–):
(3AG) No. 18 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 180 ージ 20  
AB(diag)-181
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DH:DTC B1905 SHORT IN FRONT P/T LH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Seat belt pretensioner LH circuit is shorted.
Pretensioner LH is faulty.
Pretensioner harness LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the seat
belt pretensioner LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB21).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the seat
belt pretensioner
LH. <Ref. to SB-
16, Front Seat
Belt.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB17
12
AB21
1
2
AB21
1
2
AB17
AB-03488
AIRBAG CM
PRETENSIONER LH
15WRX_STI_US_EN.book 181 ージ 20  
AB(diag)-182
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (PRE-
TENSIONER HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from the con-
nector (2N) of test harness N.
3) Disconnect the connector (AB19) from side
airbag module LH.
4) Disconnect the connector (AB31) from cur-
tain airbag module LH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) terminals in test harness AG.
Connector & terminal
(3AG) No. 10 — (3AG) No. 12:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 182 ージ 20  
AB(diag)-183
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DI: DTC B1906 OPEN IN FRONT P/T LH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Seat belt pretensioner LH circuit is open.
Pretensioner LH is faulty.
Pretensioner harness LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the seat
belt pretensioner LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB21).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the seat
belt pretensioner
LH. <Ref. to SB-
16, Front Seat
Belt.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB17
12
AB21
1
2
AB21
1
2
AB17
AB-03488
AIRBAG CM
PRETENSIONER LH
15WRX_STI_US_EN.book 183 ージ 20  
AB(diag)-184
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (PRE-
TENSIONER HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from the con-
nector (2N) of test harness N.
3) Disconnect the connector (AB19) from side
airbag module LH.
4) Disconnect the connector (AB31) from cur-
tain airbag module LH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) in the test harness AG and connector
(2N) in the test harness N.
Connector & terminal
(3AG) No. 10 — (2N) No. 1:
(3AG) No. 12 — (2N) No. 2:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 184 ージ 20  
AB(diag)-185
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DJ:DTC B1907 SHORT IN FRONT P/T LH (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Seat belt pretensioner LH circuit is shorted to ground.
Pretensioner LH is faulty.
Pretensioner harness LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the seat
belt pretensioner LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB21).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the seat
belt pretensioner
LH. <Ref. to SB-
16, Front Seat
Belt.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB17
12
AB21
1
2
AB21
1
2
AB17
AB-03488
AIRBAG CM
PRETENSIONER LH
15WRX_STI_US_EN.book 185 ージ 20  
AB(diag)-186
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (PRE-
TENSIONER HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from the con-
nector (2N) of test harness N.
3) Disconnect the connector (AB19) from side
airbag module LH.
4) Disconnect the connector (AB31) from cur-
tain airbag module LH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Measure the resistance between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 10 — Chassis ground:
(3AG) No. 12 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 186 ージ 20  
AB(diag)-187
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DK:DTC B1908 SHORT IN FRONT P/T LH (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Seat belt pretensioner LH circuit is shorted to power supply.
Pretensioner LH is faulty.
Pretensioner harness LH is faulty.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the seat
belt pretensioner LH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB21) from seat
belt pretensioner LH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB21).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for six seconds and
go off?
Replace the seat
belt pretensioner
LH. <Ref. to SB-
16, Front Seat
Belt.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB17
12
AB21
1
2
AB21
1
2
AB17
AB-03488
AIRBAG CM
PRETENSIONER LH
15WRX_STI_US_EN.book 187 ージ 20  
AB(diag)-188
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (PRE-
TENSIONER HARNESS LH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from the con-
nector (2N) of test harness N.
3) Disconnect the connector (AB19) from side
airbag module LH.
4) Disconnect the connector (AB31) from cur-
tain airbag module LH.
5) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
6) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
7) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
8) Connect the battery ground terminal and
turn the ignition switch to ON.
9) Measure the voltage between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 10 (+) — Chassis ground (–):
(3AG) No. 12 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 188 ージ 20  
AB(diag)-189
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DL:DTC B19F0 SHORT IN FRONT P/T 2 RH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Lap seat belt pretensioner RH circuit is shorted.
Lap seat belt pretensioner RH is faulty.
Lap seat belt pretensioner harness RH is shorted.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the lap
seat belt pretensioner RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK LAP SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB30) from the
lap seat belt pretensioner RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB30).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the lap
seat belt preten-
sioner RH. <Ref. to
SB-17, SEAT BELT
INNER - FRONT,
REMOVAL, Front
Seat Belt.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
AB30
12
2
1
AB30
2
1
AB18
AB-03489
AIRBAG CM
LAP SEAT BELT
PRETENSIONER RH
15WRX_STI_US_EN.book 189 ージ 20  
AB(diag)-190
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (LAP
SEAT BELT PRETENSIONER HARNESS
RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the connector (AB24) from side
airbag module RH.
5) Disconnect the connector (AB26) from seat
belt pretensioner.
6) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
7) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
8) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
9) Measure the resistance between connector
(3AG) terminals in test harness AG.
Connector & terminal
(3AG) No. 17 — (3AG) No. 19:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 190 ージ 20  
AB(diag)-191
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DM:DTC B19F1 OPEN IN FRONT P/T 2 RH
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Lap seat belt pretensioner RH circuit is open.
Lap seat belt pretensioner RH is faulty.
Lap seat belt pretensioner harness RH is open.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the lap
seat belt pretensioner RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK LAP SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB30) from the
lap seat belt pretensioner RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB30).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the lap
seat belt preten-
sioner RH. <Ref. to
SB-17, SEAT BELT
INNER - FRONT,
REMOVAL, Front
Seat Belt.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
AB30
12
2
1
AB30
2
1
AB18
AB-03489
AIRBAG CM
LAP SEAT BELT
PRETENSIONER RH
15WRX_STI_US_EN.book 191 ージ 20  
AB(diag)-192
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (SIDE
AIRBAG HARNESS RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the connector (AB24) from side
airbag module RH.
5) Disconnect the connector (AB26) from seat
belt pretensioner.
6) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
7) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
8) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
9) Measure the resistance between connector
(3AG) in the test harness AG and connector
(2N) in the test harness N.
Connector & terminal
(3AG) No. 17 — (2N) No. 2:
(3AG) No. 19 — (2N) No. 1:
Is the resistance less than 10
Ω?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 192 ージ 20  
AB(diag)-193
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DN:DTC B19F2 SHORT IN FRONT P/T 2 RH (TO GROUND)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Lap seat belt pretensioner RH circuit is shorted to ground.
Lap seat belt pretensioner RH is faulty.
Lap seat belt pretensioner harness RH is shorted to ground.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the lap
seat belt pretensioner RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK LAP SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB30) from the
lap seat belt pretensioner RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB30).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the lap
seat belt preten-
sioner RH. <Ref. to
SB-17, SEAT BELT
INNER - FRONT,
REMOVAL, Front
Seat Belt.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
AB30
12
2
1
AB30
2
1
AB18
AB-03489
AIRBAG CM
LAP SEAT BELT
PRETENSIONER RH
15WRX_STI_US_EN.book 193 ージ 20  
AB(diag)-194
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (LAP
SEAT BELT PRETENSIONER HARNESS
RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the connector (AB24) from side
airbag module RH.
5) Disconnect the connector (AB26) from seat
belt pretensioner.
6) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
7) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
8) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
9) Measure the resistance between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 17 — Chassis ground:
(3AG) No. 19 — Chassis ground:
Is the resistance 1 MΩ or
more?
Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 194 ージ 20  
AB(diag)-195
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
DO:DTC B19F3 SHORT IN FRONT P/T 2 RH (TO +B)
DIAGNOSIS START CONDITION:
Ignition voltage is 10 V to 16 V.
DTC DETECTING CONDITION:
Lap seat belt pretensioner RH circuit is shorted to power supply.
Lap seat belt pretensioner RH is faulty.
Lap seat belt pretensioner harness RH is shorted to power supply.
Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. <Ref. to AB(diag)-4,
CAUTION, General Description.>
WIRING DIAGRAM:
Airbag system <Ref. to WI-73, WIRING DIAGRAM, Airbag System.>
Step Check Yes No
1 CHECK POOR CONTACT OF CONNEC-
TORS.
Check for poor contact of the connectors
between the airbag control module and the lap
seat belt pretensioner RH.
Is there poor contact? Replace the airbag
rear harness along
with body harness.
Go to step 2.
2 CHECK LAP SEAT BELT PRETENSIONER.
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the connector (AB30) from the
lap seat belt pretensioner RH.
3) Connect the connector (1N) in the test har-
ness N to the connector (AB30).
4) Connect the airbag resistor to the connector
(2N) of test harness N.
5) Connect the battery ground terminal and
turn the ignition switch to ON.
Does the airbag warning light
illuminate for 6 seconds and go
off?
Replace the lap
seat belt preten-
sioner RH. <Ref. to
SB-17, SEAT BELT
INNER - FRONT,
REMOVAL, Front
Seat Belt.>
Go to step 3.
1524
10
9
1514
67
11 12
3
8
13
AB18
AB30
12
2
1
AB30
2
1
AB18
AB-03489
AIRBAG CM
LAP SEAT BELT
PRETENSIONER RH
15WRX_STI_US_EN.book 195 ージ 20  
AB(diag)-196
Diagnostic Chart with Trouble Code
AIRBAG SYSTEM (DIAGNOSTICS)
3 CHECK AIRBAG REAR HARNESS (LAP
SEAT BELT PRETENSIONER HARNESS
RH).
1) Turn the ignition switch to OFF, disconnect
the battery ground cable, and wait for 60 sec-
onds or more.
2) Disconnect the airbag resistor from test har-
ness N.
3) Disconnect the connector (AB33) from cur-
tain airbag module RH.
4) Disconnect the connector (AB24) from side
airbag module RH.
5) Disconnect the connector (AB26) from seat
belt pretensioner.
6) Disconnect the connectors (AB6, AB17,
AB18) from airbag control module.
7) Connect the connector (1AH) in the test har-
ness AH to the connectors (AB6, AB17, AB18).
8) Connect the connector (2AH) in the test har-
ness AH and the connector (1AG) in the test
harness AG.
9) Connect the battery ground terminal and
turn the ignition switch to ON.
10) Measure the voltage between connector
(3AG) in the test harness AG and chassis
ground.
Connector & terminal
(3AG) No. 17 (+) — Chassis ground (–):
(3AG) No. 19 (+) — Chassis ground (–):
Is the voltage less than 1 V? Go to step 4. Replace the airbag
rear harness along
with body harness.
4 CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory.
3) Perform the Inspection Mode.
4) Read the DTC. (Current malfunction)
Is the same DTC displayed? Replace the airbag
control module.
<Ref. to AB-48,
Airbag Control
Module.>
Go to step 5.
5 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed? Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
AB(diag)-33, List
of Diagnostic Trou-
ble Code (DTC).>
Finish the diagno-
sis.
Step Check Yes No
15WRX_STI_US_EN.book 196 ージ 20  
OCCUPANT DETECTION SYSTEM (DIAG-
NOSTICS)
OD(diag)
Page
1. Basic Diagnostic Procedure .......................................................................2
2. Check List for Interview ..............................................................................3
3. General Description ...................................................................................4
4. Electrical Component Location ..................................................................8
5. Airbag Connector .......................................................................................9
6. Control Module I/O Signal ........................................................................10
7. Subaru Select Monitor ..............................................................................11
8. Read Diagnostic Trouble Code (DTC) .....................................................12
9. Inspection Mode .......................................................................................13
10. Clear Memory Mode .................................................................................14
11. Read Current Data ...................................................................................15
12. Airbag Warning Light Illumination Pattern ................................................16
13. Passenger’s Airbag ON/OFF Indicator Light Illumination Pattern ............17
14. List of Diagnostic Trouble Code (DTC) ....................................................18
15. Diagnostic Procedure with Diagnostic Trouble Code (DTC) ....................19
15WRX_STI_US_EN.book 1 ペー 01